Medal of Honor
America's top military decoration, the Medal of Honor is awarded to troops for valor in combat.
"The medal was first authorized in 1861 for sailors and Marines, and the following year for soldiers as well," according to the Army's website. "Since then, more than 3,400 Medals of Honor have been awarded to members of all services and the Coast Guard."
Strict conditions were gradually established to limit awards of the medal.
"Medals of Honor are awarded sparingly and are bestowed only to the bravest of the brave; and that courage must be well-documented," the Army said.
The Distinguished Service Cross
The Distinguished Service Cross is the nation's second- highest medal for valor. It was established by law during World War I.
"The President may award a distinguished-service cross of appropriate design, with ribbons and appurtenances, to a person who, while serving in any capacity with the (military) distinguishes himself by extraordinary heroism not justifying the award of a medal of honor," federal law reads.
The Silver Star Medal
The nation's third-highest medal for valor is the Silver Star. Established during World War I as the Citation Star, the medal was renamed the Silver Star in 1932. It is awarded to members of the armed forces for gallantry in combat.
The Distinguished Flying Cross
The Distinguished Flying Cross was authorized in 1926 to recognize heroism in flight.
"The President may award a Distinguished Flying Cross of appropriate design with accompanying ribbon to any person who, while serving in any capacity with the Army, distinguishes himself by heroism or extraordinary achievement while participating in an aerial flight," federal law reads.
The Bronze Star Medal
Unlike the other valor medals, the Bronze Star can be awarded for valor and "meritorious service." It was established in 1944. Bronze Star Medals earned for valor are distinguished by a "V" device affixed to the ribbon.
The Purple Heart
The nation's oldest medal, established in 1782, the Purple Heart has been used since the 1930s to recognize troops who were wounded in combat.
In an executive order on the medal, President Harry S. Truman specified that troops receiving the Purple Heart "must have required treatment by a medical officer."