What is the Medal of Honor:
The Medal of Honor is the highest award for valor in action against an enemy force which can be bestowed upon an individual serving in the Armed Services of the United States. Generally presented to its recipient by the President of the United States of America in the name of Congress.

How did it come about?
Early in the Civil War, a medal for individual valor was proposed by Iowa Sen. James Grimes to Gen. Winfield Scott, the commanding general of the Army, who rejected the proposal. The Navy first adopted it, and legislation authorizing it was signed into law by President Abraham Lincoln on Dec. 21, 1861. A similar resolution was then introduced on behalf of the Army, and Lincoln signed it into law on July 12, 1862.

How many have there been?
Staff Sgt. Salvatore Giunta's Medal of Honor will be the 3,471st awarded. Of those, 624 have been awarded posthumously. For actions since the beginning of World War II, 855 Medals of Honor have been awarded, 527 (or 62 percent) posthumously. For actions occurring since the withdrawal of U.S. forces from Vietnam in 1973, the Medal of Honor has been awarded 10 times, nine of them posthumously, Giunta's medal being the only exception
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Additional Information:
-U.S. Army Center of Military History
-Congressional Medal of Honor Society