Cassville is a village in Grant County, Wisconsin, United States. The population was 1,085 at the 2000 census. The village is located along the Mississippi River within the Town of Cassville.
Cassville was first settled in 1827 and was named for Lewis Cass, governor of Michigan Territory at the time. After the creation of Wisconsin Territory in 1836, Cassville was viewed by many as a likely candidate to be the territorial capital, owing to its central location in a territory that stretched from Lake Michigan to the Missouri River. Land speculators built up the site, but the city of Madison, Wisconsin was selected as capital instead. This caused Cassville's developers to go bankrupt.
Eventually Nelson Dewey, who had moved to Cassville in 1836 and later served as the first Governor of Wisconsin, bought up most of the village. Hoping to profit from this, he encouraged settlement at the site to turn Cassville into a metropolis. In the meantime, Dewey was able to establish a large estate for himself outside the city. The estate, which he named Stonefield, is now a state historic site. Dewey himself was unable to occupy it for long. A fire destroyed his home in 1873, and financial misfortune forced him to sell the property shortly later. Cassville never became the major city that Dewey had envisioned. Today the city is primarily known for the Stonefield Historic Site, Nelson Dewey State Park, and the Cassville Ferry, which runs between Cassville and a nearby landing in Iowa.