Johnson County, Illinois
Johnson County is a county in the U.S. state of Illinois. According to the 2010 census, it has a population of 12,582. The county seat is Vienna. Johnson County was founded in 1812 and named for Richard M. Johnson, who was then a U.S. Congressman from Kentucky.
- "State & County QuickFacts". United States Census Bureau. Archived from the original on July 12, 2011. Retrieved July 6, 2014.
- "Find a County". National Association of Counties. Archived from the original on 2015-05-10. Retrieved 2011-06-07.
- Gannett, Henry (1905). The Origin of Certain Place Names in the United States. Govt. Print. Off. p. 169.