 He studied and was admitted to the state bar in 1847.Rather than practicing law, he pursued interests in the warehouse and commission business.After serving in the Georgia House of Representatives in 1853, 1855, and 1857, Hardeman was elected in 1858 as an Opposition Party candidate to the 36th United States Congress as a Representative of Georgia's 3rd congressional district and served a partial term from March 4, 1859, until January 23, 1861, when he resigned to become a captain in the "Floyd Rifles".