Henry Clay and Martin Van Buren , the respective front-runners for the Whig and Democratic nominations in the 1844 presidential election , both opposed the annexation of Texas . However , Van Buren 's opposition to annexation damaged his candidacy , and he was defeated by James K. Polk , an acolyte of Jackson and an old friend of Houston 's , at the 1844 Democratic National Convention . Polk went on to defeat Clay in the general election , giving backers of annexation an electoral mandate . Meanwhile , Houston 's term ended in December 1844 , and he was succeeded by his secretary of state , Anson Jones . In the waning days of his own presidency , Tyler used Polk 's victory to convince Congress to approve of the annexation of Texas . Seeking Texas 's immediate acceptance of annexation , Tyler made Texas a generous offer that allowed the state to retain control of its public lands , though it would also be required to keep its public debt . A Texas convention approved of the offer of annexation in July 1845 , and Texas became a U.S. state in February 1846
1844 Democratic National Convention
1844 Democratic National Convention
Sam Houston