White, Jesse. Origin and Evolution of Illinois Counties. State of Illinois, March 2010. "Archived copy"(PDF). Archived(PDF) from the original on August 6, 2012. Retrieved September 26, 2012.{{cite web}}: CS1 maint: archived copy as title (link)
naco.org
"Find a County". National Association of Counties. Archived from the original on May 31, 2011. Retrieved June 7, 2011.
"Find a County". National Association of Counties. Archived from the original on May 31, 2011. Retrieved June 7, 2011.
White, Jesse. Origin and Evolution of Illinois Counties. State of Illinois, March 2010. "Archived copy"(PDF). Archived(PDF) from the original on August 6, 2012. Retrieved September 26, 2012.{{cite web}}: CS1 maint: archived copy as title (link)