In February 1829, Jackson wrote to Van Buren to ask him to become Secretary of State. Van Buren quickly agreed, and he resigned as governor the following month; his tenure of forty-three days is the shortest of any Governor of New York. No serious diplomatic crises arose during Van Buren's tenure as Secretary of State, but he achieved several notable successes, such as settling long-standing claims against France and winning reparations for property that had been seized during the Napoleonic Wars. He reached an agreement with the British to open trade with the British West Indies colonies and concluded a treaty with the Ottoman Empire that gained American merchants access to the Black Sea. Items on which he did not achieve success included settling the Maine-New Brunswick boundary dispute with Great Britain, gaining settlement of the U.S. claim to the Oregon Country, concluding a commercial treaty with Russia, and persuading Mexico to sell Texas.