Greenfield is located in the state of Wisconsin and a city in Milwaukee County. As a suburb of Milwaukee, it became a bedroom community of the many other cities that are part of the Milwaukee metropolitan area. In 1839, the Town of Kinnikinnick was established by the territorial legislature, which then encompassed the western part of the Town Lake; and after which, the southern part of the town was split in order to form the town of Franklin. In 1841, the name was then changed to Greenfield after the name of the Post Office located in the Town of Kinnickinnic. Greenfield became the final municipality in Milwaukee County to Incorporate and was also the final municipality to leave the Town form of government in 1957.