 He moved with his father, David Cobb, in 1809 to Bellefonte, Jackson County, Alabama.Cobb received a limited education and worked as a clock peddler and merchant in Bellefonte before being elected to the Alabama House of Representatives in 1844.In 1846 he was elected as a Democrat to the U.S. House of Representatives from Alabama's sixth congressional district, which then included Huntsville and the mountainous counties of northeast Alabama, including Cobb's home county of Jackson, carved out of Madison in 1819.