Clinton County was formed on December 21, 1837. It was named for DeWitt Clinton, a Governor of New York and most ardent advocate for the construction of the Erie Canal. The cities of DeWitt and Clinton were also named after him.
In 1835, Elijah Buell built a log cabin for himself and his family and was thus the first settler of the region. In 1854, the first newspaper was issued and in 1858, the Lyons Female College for girls opened its doors. The tuition was set at $175 per student.
The county has used three courthouses in its history. The structure currently in use was constructed in Romanesque style and opened in 1897.
Clinton county was first settled in 1836, by Mr. Bourne, who located upon Sec. 1, T. 80, R. 4, East. The county was surveyed in 1837, by the Messrs. Burtz. The Surveyor General's office was then at Cincinnati, Ohio. In 1840, the county was organized by Sheriff Bourne. In 1841, R. R. Bed ford and others formed a little settlement at De Witt, and during the same year Messrs. Wheeler and Evans erected a log court-house. In stepping from the past to the present, we quote the language of one of the "oldest inhabitants." He says: "Clinton County was originally settled by the poorest class of people on God's earth; and it is with great pleasure that I have witnessed their progress, slow but sure, and now find the most of them very comfortably situated."
The population of this County in 1840, was 821; in 1850, 2822; in 1854, 7000; and in 1856, 11,000. The population of Lyons in 1850, was 453. In 1856 the population increased to 2700.