Clinton County, Illinois: History
In 1805, prior to the establishment of the county, the territorial government established a post road from its capital (Vincennes, Indiana) to St. Louis, Missouri, passing through the county.
In 1808 a wagon road was laid out through the future Clinton County. It extended from the Goshen Settlement to the Ohio salt works and crossed the Kaskaskia River at Carlyle. Clinton County became the home to early settlers by 1814, when the first land entries were made.
Clinton County was created on December 27, 1824, from portions of Washington, Fayette, and Bond Counties. It was named for the seventh governor of New York, DeWitt Clinton, who helped build the Erie Canal.
Crossing the Kaskaskia became much easier when the bridge now known as the General Dean Suspension Bridge was built in 1859, at a cost of $40,000. Before the bridge was constructed, crossings involved a ferry or a mud bridge. The Illinois General Assembly set aside $20,000 for bridge restoration in 1951, and in 1953 the bridge was named after William F. Dean.