Formed January 1, 1837 (17th county)
Grant County (51,950), Lancaster (3,910), Platteville (11,838)
The domed Classical Revival dark red brick and stone courthouse was built in 1902. It sits in a square at Maple, Madison, Cherry, and Jefferson streets. United States Highway 61 passes around the courthouse. Armand D. Koch is the architect. An Administration Building was added in 1998. The courthouse features a dome and faux columns. Veteran memorials are on the grounds. There was also an 1853 building in Lancaster. Grant County was formed on January 1, 1837 as the 17th county with Lancaster as the only county seat. The county is named for the river. The county seat was named for Lancaster, Pennsylvania. Grant County is the birthplace of 1 Wisconsin Governor, John J. Blaine.
Grant County government consists of a sheriff and 19 Supervisors. Two Circuit Court Judges serve Grant County. The county is located in the southwest corner of the state. Madison, Wisconsin is northeast and Minneapolis, Minnesota is northwest of the county. The Mississippi River forms its western border and the Wisconsin River forms its northern border. The county center is 6 miles Northeast of Lancaster nearer Stitzer. The county is surrounded clockwise by Richland, Iowa, and Lafayette counties and Illinois and Iowa and Crawford County.
The area of the county is 1146.9 square miles. It is 9 out of 72 in the state. It ranks 28 out of 72 in population in the state. It has a density of 45.3 persons per square mile making it 39 out of 72 in the state. Grant County has 62.0% of its population in its incorporated areas. United States Highway 18 comes from the east, Iowa County, and goes to the northwest, Crawford County. United States Highway 61 travels north to south in the county from Crawford County to Iowa. United States Highway 151 enters from the east, Lafayette County, and joins United States Highway 61 into Iowa. The county resembles a backwards capital letter D. Lancaster is located near the center of the county. Platteville is in the southeast quarter of the county. Lancaster is the county seat and Platteville is the largest city. Lancaster is 7.5% of the county population while Platteville is 22.8% of the county population. This county is in the Platteville Micropolitan Statistical Area.
Bagley
Bloomington
Blue River
Boscobel
Cassville
Dickeyville
Fennimore
Lancaster
Mount Hope
Patch Grove
Platteville
Potosi
Tennyson
Woodman
Cuba City
Hazel Green
Livingston
Montfort
Muscoda