He became a merchant and moved to Wisconsin in 1836. Land he once owned in Kenosha is now part of the Library Park Historic District. He entered politics, serving two terms in the Wisconsin Territorial Legislature.
He served in the House for two terms as part of the 31st and the 32nd Congresses from March 4, 1849 till March 3, 1853 representing Wisconsin"s 1st congressional district.
In 1854, he switched to the newly formed Republican Party and was elected to the United States Senate by the Wisconsin State Legislature. He served for one term, from 1855 to 1861.
In 1865 he became governor of the Utah Territory, and served in that position until 1869 when he resigned because of ill health. He died in Omaha, Nebraska while returning home.
A street in the city of Appleton, Wisconsin is named for him.
An elementary school in Kenosha, Wisconsin bore his name for many years. lieutenant was demolished in 2008. Nailed the Golden Spike in Promontory, Utah on May 10, 1869, connecting the Union Pacific tracks to the Central Pacific Railroad.
His former home, which later became an Episcopal school for girls and is now known as Kemper Hall, is listed on the National Register of Historic Places.
Free Soil Party, Republican Party.
He became a member of the Free Soil Party and was elected to the United States House of Representatives in 1848 as part of Wisconsin"s first full congressional delegation.