"The Medal of Honor is the nation's highest military award for bravery. It is awarded by the President in the name of Congress. For this reason, it is often referred to as the Congressional Medal of Honor. Since it was first presented in 1863, the medal has been awarded 3,512 times to 3,493 recipients. Nineteen individuals have been double recipients of the award. Recipients of the Medal of Honor are afforded a number of benefits as a result of this award. Since the award's inception, the laws and regulations that apply to it have changed. In certain cases, the award has been rescinded. Six rescinded awards have been reinstated. On a number of occasions, legislation has been offered to waive certain restrictions and to encourage the President to award the Medal of Honor to particular individuals. Generally speaking, this type of legislation is rarely enacted. In a very limited number of cases, the medal has been awarded outside the legal restrictions concerning time limits. These cases are often based on technical errors, lost documents or eyewitness accounts, or other factors that justify reconsideration. These cases, however, represent the exception and not the rule. The two most recent recipients from World War I, Army Private Henry Johnson and Army Sergeant William Shemin, were awarded Medals of Honor posthumously by President Obama on June 2, 2015."
CRS Report for Congress, 95-519
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html