Us history 1800-1876 By NathanKiblinger11 1803 Louisiana Purchase from France doubles the size of the United States. 1812 War of 1812 between the United States and the British Empire. 1820 Missouri Compromise is enacted, addressing the issue of slavery in new territories. 1830 The Indian Removal Act is signed into law, leading to the forced removal of Native American tribes. 1836 Texas Declaration of Independence. 1848 Mexican-American War. 1850 Compromise of 1850 attempts to settle issues related to slavery. 1863 Emancipation Proclamation is issued by President Abraham Lincoln. 1865 American Civil War. 1876 U.S. Centennial Exhibition in Philadelphia commemorates the nation's 100th anniversary.