Tompkins was a delegate to the state constitutional convention in 1801, a member of the state Assembly in 1803, and was elected to the United States Congress, but resigned before the beginning of the term to accept an appointment as associate justice of the state supreme court, in which capacity he served from 1804 to 1807. He was Governor of New York from 1807 to 1817. He declined an appointment as United States Secretary of State by President James Madison. He was elected Vice President on the ticket with James Monroe in 1816, and was reelected in 1820, serving from March 4, 1817 to March 3, 1825.
He was a delegate to the state constitutional convention in 1821, serving as its president. He died in Tompkinsville, Staten Island, New York, and was intered in the Minthorne vault in St. Mark’s Churchyard, New York City.