McHenry County, Illinois

McHenry County is a county in the U.S. state of Illinois. In the 2020 census, 310,229 people lived there. The county seat is Woodstock. It is the sixth-most populous county in Illinois.

McHenry County was founded in 1836 and named for William McHenry.

References

Category:1836 establishments in Illinois
Category:Illinois counties