Expansion of USA By noblepylon Nov 30, 1803 Louisiana Purchase Feb 28, 1825 Texas Annexed Apr 25, 1846 Mexican-American War Jan 24, 1848 California Gold Rush Mar 4, 1861 American Civil War Jul 1, 1868 Purchase of Alaska May 10, 1869 Completion of Transcontinental Railroad Jan 1, 1870 Formation of Standard Oil Trust Dec 2, 1886 American Federation of Labor(AFL) founded Jul 7, 1898 Hawaiian islands annexed Mar 4, 1913 Department of Labor established