War of 1812, Jun 18, 1812, 11:35am LMT, Wash. DC. Mexican War, May 13, 1846, @02:00pm LMT, Wash. DC Civil War, Apr 12, 1861, @ 04:35am, LMT, Charleston, SC Spanish-American War, Apr 23, 1898, 07:36am EST, Wash. DC. (Spanish gov't declared war first @ 12:36pm GMT in Madrid. The U.S. announced on April 25 that a state of war had existed since April 21. The explosion on the USS Maine occurred in Havana, Feb 15, 1898, 09:40pm EST. So, it's hard to know which chart to use!) WWI, Apr 6, 1917, (no time) EST, Wash DC Pearl Harbor, Dec 7, 1941, 07:55am HST/12:55pm Wash DC WWII, Dec 8, 1941, 12:39pm EST Wash DC Korean War, No. invades So. June 25, 1950 (no time), Seoul, Korea. U.N. authorizes military action, June 27, 1950 (no time), NYC U.S. troops sent to Korea, June 30, 1950 (no time), Wash DC Vietnam War, Mar 8, 1965 (first combat troops land at China Beach to help defend the airbase at Danang. There were 23,000 military advisors in VN at the time.) 1st Gulf War, Feb 24, 1991, 04:00am local time, Baghdad, Iraq. Yugoslav War, March 24, 1999, 07:56pm MET, Belgrade 9/11, Sept 11, 2001, 08:48am EDT, NYC Iraq War, Mar 20, 2003, 05:30am BAT, Baghdad.