Private practice, Pittsburgh, Pennsylvania, 1801-1806, 1808-1815, 1836-1843, 1845- , 1858-1865
Private practice, Lexington, Kentucky, 1806-1807
President, Pittsburgh [Pennsylvania] City Council, 1816-1819
State representative, Pennsylvania, 1819-1820
President judge, Pennsylvania Court of Common Pleas, Fifth Judicial District, 1820-1824
U.S. representative from Pennsylvania, 1829-1830, 1843-1844
U.S. senator from Pennsylvania, 1831-1834
Minister to Russia, U.S. Department of State, 1834-1836
Secretary of War, 1844-1845
State senator, Pennsylvania, 1855-1857