James Knox Polk (November 2, 1795 – June 15, 1849) was the 11th president of the United States, serving from 1845 to 1849. He previously was Speaker of the House of Representatives (1835–1839) and governor of Tennessee (1839–1841). Polk is chiefly known for extending the territory of the United States during the Mexican–American War; during his presidency, the United States expanded significantly with the annexation of the Republic of Texas, the Oregon Territory, and the Mexican Cession following the American victory in the Mexican–American War. After building a successful law practice in Tennessee, Polk was elected to the state legislature (1823) and then to the United States House of Representatives in 1825, becoming a strong supporter of Andrew Jackson. Polk's message was crafted to present the war as a just and necessary defense of the country against a neighbor that had long troubled the United States.The House overwhelmingly approved a resolution declaring war and authorizing the president to accept 50,000 volunteers into the military.