The Town of Sumner was established in November of 1858. Its first meeting as a Town was on the first Tuesday in April of 1859. In its earliest years, Sumner was a bustling frontier community with a grist and flour mill, a saw mill, a harness shop and a blacksmith shop. While the early business disappeared due changes in due to industrialization a fair number of the current residents are proud descendants of original settlers in the area. The names of the Town roads reflect the names of early settlers: Kumlien, Klement, Hammerquist, and Bussey to name a few. Four lake side communities which started primarily as second homes in the 20s and 30s are now thriving communities with many permanent residents who once were summer visitors, who were drawn to a quieter more rural lifestyle.

As Towns go in Jefferson County, Sumner is the smallest Town in land area, just 17 square miles. Its population at the last Census was 904 people. The geographical features include having the Rock River and Lake Koshkonong on its southern boundary and Koshkonong Creek which passes under Hwy 106 just at the outskirts of Busseyville on its way to Lake Koshkonong. State Highway 106 rambles from the City of Fort Atkinson on the east end of the Town to the county line road of Bingham on the west end. The City of Edgerton is only a few miles further down 106.

Small Sumner may be, but it has a lot to offer those with an eye for quality of life. It is a diverse community that offers things such as hunting, fishing and boating and in the winter unparalleled snowmobiling on the third biggest lake in Wisconsin. There is still a farming and agriculture community with its work ethic and community spirit. There are small farms in Sumner which offer locally raised produce and locally raised beef. And in the present, the Town of Sumner continues to offer a rural environment for both living and recreation.