McHenry County was created on January 16, 1836 (Laws, 1836, p. 273) and was formed from Cook County and unorganized (La Salle County) . Present area, or parts of it, formerly included in: Cook County (1831–1836) , LaSalle County (1831–1836) , Putnam County (1825–1831) , Fulton County (1823–1825) , Pike County (1821–1823) , Clark County (1819–1821) , Crawford County (1816–1819) , Edwards County (1815–1816) , Madison County (1812–1815) , St. Clair County (1801–1812) and Knox, Northwest Territory (1795–1801) .
The County was named for William McHenry, a pioneer of White County, soldier of the War of 1812 and the Black Hawk War, Representative in the first, fourth, fifth and ninth General Assemblies, and Senator in the sixth General Assembly. The County Seat is Woodstock . Prior County Seats was McHenry (1837–1843) and Woodstock—Named Centreville until 1844 (1843–Present) .

The Official County website is located at http://www.co.mchenry.il.us/. All departments below at located at the McHenry County Government Center, 2200 North Seminary Avenue, Woodstock, IL 60098 , unless a different address is listed below.
NOTE: The record dates below are from the earliest date to present time.
McHenry County Circuit Court Clerk has Probate Records from 1840 and Court Records from 1838 and is located at the address above. Phone Number: (815) 334-4310
McHenry County Recorder has Land Records from 1839 and is located at the courthouse. Phone Number: (815) 334-4110
McHenry County Clerk has Birth / Death Records from 1877 and Marriage Records from 1837 and is located at the courthouse. Phone Number: (815) 334-4242
County Treasurer’s responsibilities include the statutory duties required as County Treasurer and as Ex-Officio County Collector of Real Estate Property Taxes and Drainage District Taxes for the entire county.
Below is a list of online resources for McHenry County Court Records. Email us with websites containing McHenry County Court Records by clicking the link below:

Birth, marriage, and death records are connected with central life events. They are prime sources for genealogical information.
Illinois Department of Public Health, Division of Vital Records, 605 W. Jefferson St., Springfield, IL 62702-5097. It can take up to 6 weeks to get a vital record from Illinois.
A number of resources are available for individuals doing genealogical research using vital records filed in the state of Illinois. Births and deaths before January 1, 1916 and marriages before January 1, 1962 are recorded only in the office of the county clerk where the event occurred. Most county clerks have indexes to the records that are prior to 1916 that are available for the purpose of genealogical research. These indexes generally provide the name, date and place of occurrence and are located in county courthouses located throughout the state. Although self-service access to the indexes is generally permitted, the law limits physical access to the individual records to the clerk's staff. When you locate a record from the index, it will be necessary for the clerk to pull the record for you once you have paid the appropriate search fee. Please check with the county clerk for fees and policies on reviewing indexes.
Below is a list of online resources for McHenry County Vital Records. Email us with websites containing McHenry County Vital Records by clicking the link below:

Few, if any, records reveal as many details about individuals and families as do government census records. Substitute records can be used when the official census is unavailable
Countywide Records: Federal Population Schedules that exist for McHenry County, Illinois are 1840, 1850, 1860, 1870, 1880, 1900, 1910, 1910, 1920 and 1940.Other Federal Schedules to look at when researching your Family Tree in McHenry County, Illinois are Industry and Agriculture Schedules availible for the years 1850, 1860, 1870 and 1880.
The Mortality Schedules for the years 1850, 1860, 1870 and 1880.There are free downloadable and printable Census forms to help with your research. These include U.S. Census Extraction Forms and U.K. Census Extraction Forms.
Below is a list of online resources for McHenry County Census Records. Email us with websites containing McHenry County Census Records by clicking the link below:
Below is a list of online resources for McHenry County Maps. Email us with websites containing McHenry County Maps by clicking the link below:
Below is a list of online resources for McHenry County Military Records. Email us with websites containing McHenry County Military Records by clicking the link below:
There are many churches and cemeteries in McHenry County. Some transcriptions are online. A great site is the McHenry County Tombstone Transcription Project.
Below is a list of online resources for McHenry County Cemetery & Church Records. Email us with websites containing McHenry County Cemetery & Church Records by clicking the link below:
Below is a list of online resources for McHenry County Family Trees, web forums and other family type information. Email us with websites containing McHenry County Family Trees, web forums and other family type information by clicking the link below: