He presented credentials as a Member-elect to the 9th United States Congress (March 4, 1805 – December 24, 1805) but was replaced by Thomas Spalding who contested the initial election outcome. Mead then served as Secretary of the Mississippi Territory, 1806–1807; Acting Governor of Mississippi, 1806–1807; and member of the Mississippi House of Representatives, 1807 and 1822–23.
He was unsuccessful candidate for election to the 13th United States Congress in 1812. He was a delegate to the first constitutional convention of Mississippi in 1817. He was an unsuccessful candidate for election to the 16th United States Congress in 1818. He served in the Mississippi Senate in 1821. He was an unsuccessful candidate for election as Governor of Mississippi in 1825. He died in 1844 on his Geenwood plantation in Hinds County, Mississippi where he was buried.
- United States Congress. "Cowles Mead (id: M000614)". Biographical Directory of the United States Congress.