World War I lasted from April 6, 1917, to November 11, 1918; World War II from December 7, 1941, to December 31, 1946; the Korean War from June 25, 1950, to January 31, 1955; the Vietnam War from December 22, 1961, to May 7, 1975; followed by the Lebanon, Grenada, and Panama conflicts and the Desert Storm War beginning January 16, 1991.