Clarke moved to Vermont and
studied law, although the details of his relocation and studies are unknown. In addition, he was active as a merchant and in other business ventures; in 1815, he received a license permitting him to sell liquor and wine. In 1806 he was appointed Wheelock's first
Postmaster. In 1806, Clarke was admitted to the bar in
Danville. In 1808 he married Sophia Blanchard in Danville. Sophia Blanchard's sister Sarah was the wife of
William A. Palmer, who served as
Governor and
United States Senator. Palmer and Clarke became leaders of Vermont's
Anti-Masons. Clarke practiced law in Danville. An adherent of the
National Republican Party, he served in local offices including
Justice of the Peace. In 1820 he served on the
Vermont Council of Censors, the body which met every seven years to review statutes passed by the
Vermont General Assembly and ensure their constitutionality. In the 1820s, Clarke also became active in the
American Tract Society. In addition, he was an active member of the
American Anti-Slavery Society. He served as
Caledonia County Treasurer from 1822 to 1824, and Caledonia County
Assistant Judge from 1824 to 1825. In 1826, he was appointed president of the Caledonia National Bank, succeeding Palmer, who had been the bank's first president. Clarke represented Danville in the
Vermont House of Representatives in 1824, 1828, 1830, and 1832. In 1830, Clarke was appointed one of Caledonia County's three Commissioners of Jail Delivery. Clarke was named to the Committee to Erect the
State House in 1832. He took part in planning and overseeing construction of the Second State House, which was in use from 1833 until it was destroyed by fire in 1856. Clarke was one of the founders of the Anti-Masonic movement.
William Wirt carried Vermont as the
1832 presidential candidate of the Anti-Masonic Party. Clarke was one of Vermont's
electors, and cast his ballot for Wirt. ==Later career==