Timeline of Wars By Terre12 Sep 1, 1774 Revolutionary War started Sep 3, 1783 Revolutionary War ended Jun 18, 1812 War of 1812 started Mar 23, 1815 War of 1812 ended Apr 25, 1846 Mexican-American War started Feb 2, 1848 Mexican-American War ended Apr 12, 1861 American Civil War started Aug 17, 1862 Dakota War of 1862 started Dec 26, 1862 Dakota War of 1862 ended Apr 9, 1865 American Civil War ended Jun 1, 1871 Korean Expedition started Jul 3, 1871 Korean Expedition ended Jul 6, 1872 Modoc War started Jun 4, 1873 Modoc War ended Apr 25, 1898 Spanish-American War started Aug 12, 1898 Spanish-American War ended Jun 2, 1899 Philippine-American War started Jul 4, 1902 Philippine-American War ended Apr 25, 1914 World War 1 started Apr 25, 1918 World War 1 ended Dec 7, 1941 World War 2 started Sep 2, 1945 World War 2 ended Apr 25, 1947 Cold War started