US History Timeline By 18880 Jul 4, 1776 US Independence Sep 17, 1787 Constitution Finished Jun 21, 1788 Constitution was Ratified Jul 4, 1803 Lousiana Purchase Aug 21, 1831 Nat Turner's Rebellion Mar 2, 1836 Texas Independence Feb 2, 1848 Treaty of Guadalupe Hidalgo Sep 15, 1850 Compromise of 1850 Mar 6, 1857 Dred Scott Case Dec 20, 1860 South Carolina Secession Sep 17, 1862 Battle of Antietam May 18, 1863 Battle of Vicksburg Jul 1, 1863 Battle of Gettysburg Apr 9, 1865 End of the Civil War