The Medal of Honour was created during the American Civil War and is the highest military decoration presented by the United States government to a member of its armed forces. The recipient must have distinguished themselves at the risk of their own life above and beyond the call of duty in action against an enemy of the United States.
Due to the nature of this medal, it is commonly presented posthumously. By the end of World War 1, 119 men had been awarded the Medal of Honour for supreme courage; 90 from the Army, 21 from the Navy, and eight from the US Marine Corps. Of the men awarded the Medal of Honour - for 33 it was a posthumous award. Among the recipients were Sergeant Alvin York, and the fighter ace Edward "Eddy" Rickenbacker, while the first US Marine Corps pilot to win the Medal of Honour was Ralph Talbot.
In World War 2, 464 United States military personnel received the Medal of Honour, 266 (over 50%) of them posthumously. Seventeen of these were Japanese-Americans fighting in both Europe and the Pacific, many of these recipients were upgraded from Distinguished Service Crosses during the Clinton administration.
Douglas Albert Munro from the United States Coast Guard was the only serviceman to receive the Medal for his actions during the war.
The earliest action for which a US serviceman earned a World War II Medal of Honour was the December 7, 1941, attack on Pearl Harbour, for which seventeen US servicemen were awarded the Medal of Honour.
The last action to earn a contemporaneous Medal of Honour prior to the end of hostilities in World War II, was that of Melvin Mayfield, on July 29, 1945 – though several 'honoree's may have been cited for their Medal after Mayfield's recognition on May 31, 1946.
Additionally, seven African American and twenty-two Asian American veterans who had received the Distinguished Service Cross during the war were awarded the Medal of Honour in 1997 and 2000 — most of them posthumously — after two studies determined that racial discrimination had caused them to be passed over at the time they won the Medal.