Janesville is a city in southern Wisconsin, United States. It is the county seat and largest city of Rock County, and the principal municipality of the Janesville, Wisconsin, Metropolitan Statistical Area. As of the 2010 census, the city had a population of 63,575.
According to the United States Census Bureau, the city has a total area of 34.45 square miles (89.23 km2), of which 33.86 square miles (87.70 km2) is land and 0.59 square miles (1.53 km2) is water. The city is divided by the Rock River....
Source: Wikipedia (as of 04/11/2019). Read more from Wikipedia