Jefferson is a city in Jefferson County, Wisconsin, and is its county seat. It is located at the confluence of the Rock and Crawfish Rivers. The population was 7,338 at the 2000 census. The city is located partially within the Town of Jefferson.
The location of Jefferson was selected to make use of the water power and transportation opportunities offered by the Rock River. It was the furthest point that a steamboat was able to navigate the Rock, in 1884. Unfortunately for Jefferson, that was the only time it was visited by a steamboat, as bridges were built downstream that prevented navigation.
During World War II, Camp Jefferson, a prison camp for German POW's, was erected at the Jefferson County Fairgrounds. The Jefferson County Fairgrounds hosted horse buggy racing prior to the renovations to the new fairgrounds.