How to Research Your Property

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McHenry County Property Research Resources

Want to know the history of a house, farm, store or property? Looking for a photo of your home back in time and information about previous owners? Hoping to restore it to its original look and floorplan, and determine who built it?

People searching for old photos, blueprints and previous owners of a parcel or house are the most frequently asked types of research requests at the McHenry County Historical Museum. Unfortunately, the success rate varies greatly. Not everyone gets everything answered. Hopefully, at the time of purchase, you asked the sellers for any information they had. That includes property abstracts, old deeds, names of previous owners and pictures, and old letters or papers with information about the house or any of its owners.

To start the research, the most critical piece of information, even more important than the address, is the legal description of the property, including the Parcel Identification Number (PIN). The legal description will be a block and lot number in somebody’s subdivision in municipalities or a portion of the Section, Township, and Range for larger parcels. This information is on the property tax bill. How you proceed from there depends greatly on whether you are searching a house downtown or in a rural area, where your property is in the county, how old you think your house is, etc.

The following questions may yield some answers:

  1. What is available online?
  2. What can McHenry County Historical Society offer?
  3. What resources are available at other institutions?


1. Treasurer’s website:  (

Search options include address, parcel number, and owner name, but search terms are tricky, and it doesn’t always seem to work. But it can give you a short sales history, the tax bill, payment history, taxing bodies, and assessments.

Click on the parcel GIS information button on the right to be taken to your exact parcel in the digital geographic mapping system, Athena. It is much easier than starting in Athena cold.

Athena can give you map layers of soil, flood zone, topography, and parcel text which is interesting and may be helpful but not pertinent to property history. In the upper right of the screen, click on property information. Then press down on the mouse on your parcel. Your results will come up in a box. If you press down on only one parcel, there should be only one result. Click on show details in the box of results for the correct parcel number. You’ll get a box in the upper right of the screen with four tabs. The first tab on the left is details, which already shows you the PIN, parcel number; address, and owner name. The second tab is tax information, but you already got that from the treasurer’s website. The third tab is miscellaneous. Here you get the last sales date and price but, most importantly, the legal description of your property. The fourth tab is documents. Any post-2011 documents are available here in .pdf, but for pre-2011 documents, you must go to the recorder’s office in the county government center annex in Woodstock.

  1. Going directly to Athena:   ( 

Zoom in and pan until you recognize your parcel. It’s trial and error if you’re looking by address instead of the parcel number. When you find the suitable parcel, then proceed as above.

         3. Recorder’s Office:  (

Free web search is your first option and only free option. You have several search options, some of them being by name, by name with date, or by subdivision and lot number. Searching is touchy and results can be very time-consuming to slog through before you find the right one. You can’t search by asking for the two people involved in a transaction. You are limited to a single name. Each result will include the document number, document type, date, party 1 (seller), party 2 (buyer, often a bank), and legal description (often multiple, which you then have to click on to see the list). If you click on the document, you’ll get a bit more information, but for the document itself, you’ll have to pay for it on Tapestry or go to the Government Center in Woodstock. The site is not for the easily frustrated. Searching on the computers at the recorder’s office is more accessible and the staff will help.   

        4. Plat Maps/Atlases:

The distinguishing feature of these products is that they show landowners’ names in rural areas. The earliest of these are sheet maps. Later types are bound atlases or plat books. Both types show property boundaries and who owns the parcels. Researchers need to understand the Public Land Survey System (Township and Range System with section numbers) to use these, although the name of the civil township usually appears on the maps as well.

The earliest landownership product for McHenry County is the 1862 sheet map. It is online HERE. Keep zooming in until you can read the fine print. You can print from it but mine always come out distorted. Vignettes of some of the county’s more famous old houses appear around the margin of the map, such as Marengo’s Hibbard house, Nunda Township’s Stickney and Terwilliger houses, Crystal Lake’s Crow house, and Chemung Township’s Hutchinson house.

Next is the first bound atlas, the 1872, online HERE. Or you can search in your browser for the 1872 McHenry County Illinois atlas and choose the Historic Map Works choice. It’s also on the McHenry County government website, courtesy of Jim Heisler. This atlas and the following two are published one township per page usually. On the Historic Map Works site, there are four tabs. You’ll default to the Maps tab. You can then click on any of the township or town map pages you see in color. The town maps do show parcels but not the owners’ names. You can zoom in and print. The three other tabs are Directories, History, and Illustrations. The Illustrations are the artists’ drawings of many of the finer houses and farms in each township. The subject of the drawing had to pay to be included.

The next atlas is the 1892, online HERE. Or again, just search in your browser for the 1892 McHenry County Illinois atlas and choose the Historic Map Works choice. Your choices for this atlas are just Maps and Directories tabs.

The last atlas accessible from Historic Map Works for free is the 1908 version. This one is in black and white. The tab choices are Maps, Directories, and Illustrations. The illustrations, in this case are photographs of private houses (identified only by owners’ names) and public structures, such as churches, factories, or shops. 

  1. Aerial Photographs:

The earliest aerial photographs for McHenry County date to 1939. The images are at a 1:20,000 scale, so they are not as detailed enough to see structures. They do not show property boundaries, names of landowners, street names, or township/section boundaries. They offer only what the camera in the airplane saw on the ground. They show natural features (water and tree cover) and structures at that point in time.

The McHenry County 1939 photos are online HERE. You’ll get a list of counties and the option of looking at them in JPEG or TIFF. Unless you want to wait a while for the .tif to download, choose McHenry and .jpg. You’ll see a blue box with blue numbers inside it, plus a choice of photomosaic or line indexes to the photos in the upper left of the screen. On the line index, towns are labeled, so you have a rough idea of where you are in the county. You can choose the photo from either type of index, but you have to go back to the blue box to click on a blue number before seeing the photo. If you chose the wrong one, go back to the index and start over. The last part of the photo number shown on each of the indexes is the blue number you click on in the blue box. There is an overlap in the photos, so make sure you get the photo with your property in the middle of the image.

The University of Illinois at Urbana-Champaign has aerial photos from more recent years, but these are not online. The online list of its online collection can be found HERE. Contact the university’s map library for further instructions.

  1. Purchases from the General Land Office:

After the Northwest Ordinance passed Congress in 1785 and the Public Land Survey System was established, surveyors such as John Brink, tromped through the land dividing it into township, sections, quarter sections, and so forth back in the late 1830s and early 1840s. This had to be done across the Northwest Territories before land could be sold to settlers in an orderly fashion. The federal government recorded the sales of these properties in tract books. Unfortunately, these records only show the first purchaser of that land. This is who you ultimately want to find,  but you could start here and go forward in time.

The Illinois State Archives has turned these tract books into a database online HERE. You can search in two ways: by legal description or by the name of the purchaser. To search by legal description, you need to know that you’re in the 3rd principal meridian, which township by number, always north for McHenry County, which range by number, always east for McHenry County, and section number 1 through 36. After inputting all that, you’ll get a list of names alphabetically of those who purchased land in that section, with the date of purchase and the portion of that section purchased. Pick one of those names to get the individual record for the purchase showing the number of acres purchased and the price per acre plus the total price of that sale. To search by name, which you probably don’t have but may verify when you do get back to the beginning, enter the name (last name first, no comma, first name) with or without choosing McHenry County. You’ll get a list of names and the section and portion of the section in which they purchased property. (To understand the portion of the section entry, you have to know to read legal descriptions backward. For instance, NWSE would mean he purchased the northwest corner of the southeast quarter section. You have to look at the map of Section 5, for example, then find the southeast quarter of Section 5 and then the northwest corner of that southeast quarter). Then you can click on a specific name again for an individual record.

          7. McHenry County Rural Structures Surveys:



All townships are represented HERE. They may be separated by date. The latest ones are called Rural Intensive Surveys, and earlier ones are called Rural Structures Surveys. The resources you can choose from depending on which survey covered your township. You can check the site list (with PIN or address), the sketch map for the township, or area detail, depending on which year your township was surveyed. Check these to see if your property is included in these surveys. The information you want is in one comprehensive list with details for later years. You can go further into the individual record files if it's an earlier year. The individual files are grouped into large files. The individual records are not legible but can tell you details about the property. Here, you can also access the 1983 County Landmark Survey and the 1972 and 1974 Historic Structures and Landmarks Surveys.

  1. Digital Newspaper Collection at the McHenry County Historical Society: The Society and partners are funding the digitization of local McHenry County newspapers. At this time, the free  digitized collection available HERE includes:

            Marengo – a) all issues of all titles on the microfilm owned by the Marengo-Union Library District up through 1923, b) all issues of all titles held in hard copy by the Society up through 1923.

            McHenry – a) all issues of the microfilm of the McHenry Plaindealer held by the McHenry Public Library up through 1923, b) all hard copy issues owned by the Society of the McHenry Star 1988-1998.

            Richmond - all hard copy issues of all titles that the Society owned up to 1985.          

            Woodstock – in progress.

Upon entering the digitized collection, you will default to Simple Search. You put in your search term, and then you can choose whether to have the search run in all fields or choose from multiple fields. For example, you can add a date to your simple search. You can search only the Marengo collection, the McHenry collection, the Richmond collection, or all collections. Your search results show all the pages in which your search term appears. You click on each image to see your search term highlighted in yellow. Options other than Simple Search are Browse Titles and Browse Collections. In Browse Titles, you can search for a specific year, month, or day so that you could see all the newspapers in the database for a particular day. There are many other search options, such as a publisher or specific newspaper title.

  1. Harvard Digital Newspaper Collection: You can search for a specific term and add a date, or browse by a particular newspaper title or a specific date HERE
  2. Sears Homes: Sears kit homes in Crystal Lake are documented HERETips on how to tell if your house is a Sears home are at
  3. Landmark Lists: The McHenry County Historic Preservation Commission’s list is available HERE. Some of them are residences, and two of them are farms. The McHenry County Historical Society’s list of plaqued sites is shown HERE.
  4. Walking Tours:

Algonquin Historic Commission’s Old Town Walking Tour is available HERE.

McHenry Landmarks Commission’s Historic Old Town Walking Tour is accessible HERE.

McHenry Landmarks Commission’s Historic Gagetown Walking Tour is HERE.

                13. Centennial Farms: HERE. Just choose McHenry from the drop down box, and you get a list of all the centennial farms  alphabetically by family name.

What the McHenry County Historical Society Can Offer

  1. Plat Maps/Atlases:

The Society owns the 1862 M.H. Thompson & Bros. plat map, the 1872 Everts, Baskin & Stewart atlas, and the 1892 and 1908 George A. Ogle & Co. atlases, all in hard copy, plus the reprint of the 1872 atlas. Unfortunately, even the reprint is out of print. Next chronologically are the plat books by W.W. Hixson. Hixson did not date his plat books, so the information in them can be anywhere between 1910 and 1940. Hixson’s black and white plat books contain only the township pages and are not as ornate or as large as the earlier atlases. Thrift Press published a 1927 atlas. This one is only township pages as well. The towns or urban areas on any township page are hash marked, so there are no names and no parcels either. These are strictly for rural areas. Stacy Map Publishers put out a couple of atlases for McHenry County with credible dates of 1939 and 1947. These are the same model as Hixson. Rockford Map Publishers took over Illinois plat book published in 1951 and they continue to be the primary publisher today. Early, they are simply township pages on the Hixson model. As McHenry County grew, they added street indexes, subdivision indexes, owner name indexes, and other types of maps such as taxing district, school district, soil, and highway maps. Recently, they have divided each township by quarters, so it takes four pages to cover a township but still only hash marks in the towns. The newest upgrade is the aerial photo-based maps on the page opposite that quarter of the township. A few other companies, such as Town & Country and Farm Plat Book, fill in the chronological gaps in the holdings of Rockford Map Publishers or provide a second version of the same year.

The earlier maps/atlases show not only property owners, never renters, but structures as well. So you can detect roughly when a building was constructed on the property by following that property from the 1862 map through the 1908 atlas if the property is rural.

  1. Sidwell Studios Plat Books:

Hixson branched into much more detailed plat books in the 1930s, but Sidwell Studios bought them out. Sidwell produced plat books in hard copy for many years but mainly does digital products now for customers. Their plat maps show property boundaries only, not landowners. They are large-scale maps showing the land in much more detail than the previous plat books. The earliest one MCHS has is 1951. These atlases were published in a loose-leaf format so that the company could issue correction pages to subscribers to keep the atlas up to date without republishing the whole atlas. Or sometimes, just clear patches were mailed out to be pasted onto existing pages. MCHS has several subsequent editions so researchers can follow the subdivision of farmland into housing developments and detect when a street was added to the landscape. Usually, there aren’t houses until there’s a street. Each atlas has an index to subdivisions in it. So if you find, according to your property tax bill, that you are Lot 40, Block 2 of Howell’s Villas subdivision, you can look in the index and go immediately to the appropriate page for that subdivision. MCHS has several editions of post-bound plat books into the 1990s, but they are not always the whole county. We also have loose sheets from the 1980s and 1990s. MCHS also has select Sidwell sheets based on aerial photography from the 1970s through 1995.

  1. Sanborn Fire Insurance Atlases:

Sanborn was the dominant company for fire insurance mapping in Illinois. These atlases are the urban counterpart to the rural plat books. They were published by the town. The earliest one for McHenry County varies by town. Crystal Lake’s earliest was 1893 and the latest was 1955. In between, there was the 1898, 1912, 1921, 1929, and 1936. MCHS has the original hard copy Crystal Lake 1929 and 1936, Hebron 1922, Huntley 1919, Marengo 1912 and 1925, and Woodstock 1885, 1898, and 1932 atlases, but they are in poor condition. Also on file at MCHS are black and white paper copy of the atlas sheets for Algonquin’s 1929, Cary’s 1929, Crystal Lake and Nunda’s 1893, Harvard’s 1885, Marengo’s 1885, North Crystal Lake’s (including Crystal Lake) 1912, Richmond’s 1912, and Woodstock’s 1885, 1893, 1898, 1905, and 1912 atlases. These atlases show specific buildings, what they were made of, whether a structure is a dwelling, shop, restaurant, or hotel, whether one story or two, etc. So if your building of interest is lucky enough to be shown on these maps, you can trace when the porch or garage was added. You can see the change in usage of 109 W. Front St. in Harvard over the years or the layout of Camp Algonquin in its heyday. But they don’t cover all of what’s in the city limits today. Back in 1893 what’s in town now wasn’t then. It was out in the boonies. And there had to be a big enough concentration of buildings worth buying insurance for. An atlas of only four pages in 1893 might be 12 pages by 1955. On the first page each year is the index map, which consists of a sketch map of the town and lines drawn over it to show which page of the atlas that section of town is on. There is also usually a text index showing which page of the atlas the Immanuel Lutheran church or the Borden Dairy plant is on. The atlases also show house numbers and street names of the time.

All of these atlases were microfilmed in black and white by a commercial company. The microfilmed atlases were then digitized by another company. MCHS has all available digitized Sanborn atlases for McHenry County on a thumb drive plus the 6 atlases from 1893 to 1948 for McHenry on a disc. The MCC library in Crystal Lake has the entire digital Illinois Sanborn collection available to use for free to anyone on site.

  1. Township Assessors’ Ledgers:

For all 17 townships, MCHS holds the original tax assessors’ ledgers. These dates from the founding of civil townships in Illinois in 1850 to about 1960 for most of the 17. From 1850 to 1870, there are almost annual editions. After that the holdings are less frequent. Each ledger is arranged by township and range and show who paid the taxes on specific properties, so usually who owned the property. The tax assessor also filled out columns on the number of acres and the value per acre. Theory is that if the amount owed/paid on a property jumps drastically between a certain year and the next, it’s a good bet that a structure was erected between those years. I haven’t found that to work as well in practice. I have found the property tax to go down as well. MCHS also has the 1846 and 1847 ledgers for personal property tax for the whole county. These are each a single alphabet of names for the whole county with their legal property description followed by how many stud horses, oxen, hogs, sheep, carts & carriages, thrashing machines, clocks, and watches they owned.

  1. County Recorder’s Office Records:
    1. General Mortgagor Index from 1841-1956 (17 volumes)
    2. Plat books of subdivisions, highway dedications, and some rights-of-way from 1900-1960 (14 volumes)
  2. Aerial Photographs:

MCHS has enlarged prints for all of McHenry County of the 1939 photos. MCHS also has a partial set of enlarged prints for 1961, mostly for the eastern side of the county.

  1. General Land Office Plats: 

When the surveyors hired by the General Land Office got back from the field in the late 1830s/early 1840s, they drew maps of their surveys. These maps do not show property boundaries except for section lines but they do show prairie versus timber lands, swamps, early roads, and the occasional squatter. They were drawn so that the land could be sold to settlers. MCHS has negative prints of these plats for all townships as well as color prints.

  1. General Land Office Patents:

These were issued to the first purchaser of the land from the federal government. MCHS holds a few of these oversize documents. They are arranged at MCHS by township and name of the purchaser. They simply convey ownership of the 160 acres, for instance, from the federal government to John Doe for the price of $1.25 per acre and are signed by the U. S. President of the time.

  1. Title Abstracts:

An abstract of title is the condensed history of the title to a particular parcel of real estate, consisting of a summary of the original grant and all subsequent conveyances and encumbrances affecting the property and a certification by the abstractor that the history is complete and accurate. The title company that issued the title has probably run a title search on the property. A chain of title would be very helpful for house history research, but it may be costly. MCHS holds about a dozen shelves of hard copy title abstracts. These are arranged by township name, section number, and then by surname of the first owner. They are cataloged and therefore accessible by name of the first owner, which is not often known when starting the property research.

  1. McHenry County Rural Structures Surveys:

MCHS has originals of the 1998 survey. The binders contain photos and detailed information on the structures found in the survey. The binders include a sketch map showing the location of the structures documented. Unfortunately, the 1998 survey was just these 4 townships: Algonquin (1 volume), Grafton (1 volume), McHenry (2 volumes) and Nunda (2 volumes).        

  1. Vertical Files:
    1. Subject: MCHS has extensive vertical files on subjects. Some of the subjects useful to property researchers are:

-Houses – [town]

-Farms – [town]

-Barns – [township]

-Hotels – [town]

-Restaurants – [town]

-Hardware Stores – [town]

-Antique Shops – [town]

For the more well-known houses, hotels, or restaurants, there are separate files, such as Crystal Lake’s Palmer House or Dole Mansion or Marengo’s Cloven Hoof restaurant.

           -Real estate transactions – [town]

These files may contain newspaper articles on houses that have been written up, usually with photos in the articles, or original photographs of the houses or barns. MCHS has the photos from the 1997 Year of the Barn.

    1. Biographical: MCHS has extensive biographical files. These may contain house interior or exterior photos or deeds, but you need to have a surname to enter. There are numerous photos of the Patrick houses in Marengo, for instance. But this only works for more prominent families. Not every house has been photographed.
  1. City Directories:

The value of city directories is that they are searchable by street address. Unfortunately, MCHS holds them only for Woodstock. The collection starts with 1916, jumps to 1935-36, and contains 2 or 3 directories per decade through the 1970s, then 1980 and 1990. If there is no Wright St. in the 1916 directory, then there probably was no house on Wright St. yet.

  1. House Histories:

Most local libraries, including MCHS, own the Northwest Herald’s Historic Homes of McHenry County. These are not the everyday house.

The only comprehensive study of one town’s houses that MCHS owns is the two volume History of Marengo Homes. Volume 1, in its second edition, covers the houses on Prairie and Washington streets and Volume 2 covers Grant Highway (Highway 20) and a few other streets . Each house covered has a couple paragraphs on who built it and the owners up to the 1990s. Volume 2 is out of print but MCHS has copies to sell of Volume 1.

  1. Kent Files:

MCHS was given the vertical files of the McHenry realtor, Roy Kent, who was in business from 1923 to 1951. These are arranged by surname. These sound like they should be very useful but I haven’t struck gold yet.

  1. Blueprints:

MCHS holds one drawer of miscellaneous residential blueprints. Obviously, this is a very select group. MCHS also holds over 400 blueprints from the Ewald Associates architectural firm. Some represent work done on residences. These are accessible by name of the house owner at the time.

  1. Telephone Directories:

MCHS holds a good collection of telephone books for all towns, depending on the town, back to the early 1900s. Telephone books in the early days were only the white pages we are familiar with today, and didn’t include the classified yellow pages for businesses that we know today. The white pages are surnames listed alphabetically with address and phone number following. So they are only useful when you are trying to verify that John Doe lived in Marengo in 1961, for instance. They won’t be useful if you only have an address.

There are a few early 1900s phone books for general McHenry County. 

  1. Local History Books:

The books published for local towns by the Arcadia Publishing Company in their Images of America series include photos of select structures and brief histories, such as the Riverside Chocolate Factory in McHenry in McHenry and McCullom Lake and the Rogers and Woleben homes and the Shearer Pharmacy in Marengo, the First 100 Years. These titles are listed along with other municipal history publications held by MCHS at MCHS’ website

  1. Picture Postcards:

MCHS has a collection of picture postcards for most of the county’s towns. Many are of historical structures. Many of the Crystal Lake postcards are also held by the Crystal Lake Historical Society and a lot of those are published in Diana Kenney’s Crystal Lake, published by Arcadia in its Postcard History series.


What Selected Other Institutions Offer

  1. Woodstock Public Library:
    1. Vertical files for historic houses filed by street for Woodstock
    2. City directories for Woodstock from 1922/23 on in addition to 1914
    3. 1872, 1892, and 1908 plat books
    4. Illinois edition for patrons remotely and anyone on site – building permits begin to show up in newspapers in the late 1950s and the farms changing hands were reported usually between February 1 and March 1
    5. Haines Chicago Far North Suburban Criss-Cross Directory from 1977 forward
    6. Woodstock newspapers on microfilm
    7. Telephone books for Woodstock from 1948 forward
  2. Crystal Lake Public Library:
    1. 1862 plat map, 1872, 1892, 1908, 1927 and later plat books
    2. 1931-1959 and 1980-2010 Crystal Lake phone books
    3. Illinois edition for patrons remotely and anyone on site
    4. Haines Chicago Far North Suburban Criss-Cross Directory from 1977 forward
    5. Crystal Lake newspapers on microfilm
  3. Crystal Lake Historical Society:
    1. Federal land tract books for Crystal Lake and vicinity
    2. Street files for Crystal Lake
    3. Trolley Tour booklets – short histories of the houses and structures on the annual tour
    4.  Crystal Lake telephone books
    5. Digital Sanborns for Crystal Lake
    6. full edition
    7. Digitized Herald newspaper up to 1980 – It is not searchable by subject. It is accessible only by date. But if you found what you want in or the microfilm and just can’t read it, you can look up that date in this database and get a much more legible copy usually.
  4. McHenry Public Library District:
    1. 1872, 1892, and 1908 McHenry County atlases plus plat books from the 1990s to 2019
    2. Illinois edition for patrons remotely and anyone on site
    3. Subscription to Historic Map Works, which provides access to McHenry County plat books from the 1872, 1892, and 1908 atlases and all the Rockford Map Publishers editions from 1951 to the second to latest. It also offers plat books, bird’s-eye views, directories, and maps from all states, historical maps from foreign countries, and much more. Accessible to anyone visiting the library or remotely for patrons.
    4. McHenry Plaindealer on microfilm
  5. Huntley Area Public Library District:
    1. Local history collection includes information about local houses
  6. Marengo-Union Public Library District:
    1. History of Marengo Homes (2 volumes)
    2. Marengo newspapers on microfilm
  7. McHenry County Conservation District’s Glacial Park Research Library in Ringwood:
    1. Their most unique holding is the General Land Office surveyors field notes on microfilm. They are exactly what they say they are, the surveyor’s notes when he was in the field. These are the notes from which they drew the plat map.
    2. They also have microfilm of early local newspapers.

For more information about Plaquing Your Historic Home, visit Historical Site Plaquing