The Mexican-American War By lupe0714 Aug 12, 1821 Stephen Austin moves 300 families to Texas Apr 13, 1834 Stephen Austin goes to Mexico City to press for Texas statehood Apr 30, 1836 Texas gains its independence Nov 5, 1844 James K. Polk is elected president May 13, 1846 The Bear Flag Republic is declared Sep 15, 1847 Mexico City surrenders