He was thus able to win the nomination over James Buchanan, who became his Secretary of State, as well as pre-convention favorite Martin Van Buren.  
This man's presidency saw the establishment of the Naval Academy at Annapolis by his first Navy Secretary, George Bancroft.  He was nominated with the help of Robert Walker, his future Treasury Secretary and tariff namesake, who reinstated the need for support of two-thirds of convention delegates.  He was thus able to win the nomination over James Buchanan, who became his Secretary of State, as well as pre-convention favorite Martin Van Buren.  He then won the general election over Henry Clay.  For 10 points, name this man whose term saw the signing of the Oregon Treaty and the Treaty of Guadeloupe Hidalgo, a "dark horse" who was elected in 1844.
This man's presidency saw the establishment of the Naval Academy at Annapolis by his first Navy Secretary, George Bancroft.  
James Knox Polk