The Clinton area was first settled in April, 1837 by Charles Tuttle, William Murray, Milton Warner, and Dr. Dennis Mills. These gentlemen claimed the area for the Jefferson Prairie Company, named after their home county of Jefferson in New York State. They were joined in June of that year by Mr. and Mrs. Stephen Downer and Mr. and Mrs. Daniel Tasker.
The Yankee settlers staked claims in the area that came to be called Clinton Corners, located at what is now the intersection of County Highways X and J, less than a mile west of present-day Clinton. Another early settler was Ole Knutson Natestad who arrived in the area in 1838. He was joined by his brother Ansten and several other Norwegians in 1839. The Norwegian settlement was just south of Clinton near the present Wisconsin-Ilinois state line. This settlement, along with one at Luther Valley to the west, were the first Norwegian settlements in Wisconsin and the fourth in this country.
In 1839 an act of the Wisconsin Territorial Legislature established Rock County as an "organized county of the territory," and county officers were elected in March of that year. Clinton Township was created by the legislature as a unit of local government in 1842. Both the Townships of Bradford and Turtle were similarly created in 1846, and two years later Wisconsin became a state.
In 1843 the U.S. Postal Department established post offices at Clinton Corners and nearby Summerville. That same year a school was constructed at what is now the intersection of Allen Street and Milwaukee Road.
The first religious services in the area were held in the home of Charles Tuttle in 1839. In 1844 a Methodist Church was constructed in Summerville and was later moved to Clinton Corners. The Jefferson Prairie Lutheran Church was organized in 1844, with a building constructed near the present-day stateline in 1848. During that same year a Baptist Church and a school were built at Clinton Corners.
By the early 1850's Clinton Corners had a general store, Grange building, dane hall, shoe shop, blacksmith shop, hotel, and a tailor shop, along with the churches, school, and post office. Many settlers had arrived in the area, so that by 1855 there was a population of 1,359 spread throughout Clinton township.