Vassar is a city in Tuscola County in the U.S. state of Michigan. Founded March 1, 1849. The population was 2,697 at the 2010 census and 2,823 in 2000 (a decrease of about 4.5%). The city is located on the western edge of Vassar Township but is politically independent.
According to the United States Census Bureau, the city has a total area of 2.18 square miles (5.65 km2), of which 2.12 square miles (5.49 km2) is land and 0.06 square miles (0.16 km2) is water. The Cass River flows through the city.
It is considered to be part of the Thumb of Michigan, which in turn is a subregion of the Flint/Tri-Cities. (Source, Wikipedia)