The Purple Heart is the oldest American military decoration for military merit and honors the men and women who are of the Military Order of the Purple Heart.

An accurate and complete list of recipients no longer exists, but according to the National Purple Heart Hall of Honor, about 1.9 million service members have earned Purple Hearts since its creation. It is the oldest U.S. military honor still bestowed upon service members.

Until 1944, the Purple Heart recognized service members’ commendable actions but in 1944, the requirements were changed to limit the award only to those wounded or killed in combat.

1. George Washington created the Badge of Military Merit, which is considered the predecessor of the Purple Heart. Washington designed the Badge of Military Merit in the form of a cloth purple heart, and decreed the award should be given to soldiers who displayed “not only instances of unusual gallantry in battle, but also extraordinary fidelity and essential service in any way.”

2. The award got its “modern look” in 1932. Army Gen. Douglas MacArthur wanted to refresh and rename the award in time for the bicentennial of George Washington’s birthday. The Washington Commission of Fine Arts and Elizabeth Will, a heraldry specialist in the Army’s Office of the Quartermaster General worked with MacArthur to come up with the current design.

3. It wasn’t until 1942 that all branches of service were eligible to receive the Purple Heart. The award was originally designated for the Army or Army Air Corps only. in 1942, President Roosevelt and the War Department further defined the qualifications for award, designating it for those who were wounded or killed in action. In addition they gave authorization for posthumous awards.

4. A nurse at Pearl Harbor became the first woman to receive the honor in 1942. Army Lt. Annie G. Fox receive a Purple Heart for her heroic actions during the Japanese attack on Pearl Harbor in 1941. Fox calmly and resolutely directed hospital staff to tend to the wounded as they came in from the harbor in her role as chief nurse at Hickam Field, Hawaii.

5. Animals have been awarded the Purple Heart. Sergeant Stubby the dog and Sergeant Reckless the horse received Purple Hearts. Famous humans have also received the Purple Heart, including actors James Arness, Charles Bronson, James Garner, and Rod Serling, author Kurt Vonnegut, director Oliver Stone and athletes including baseball player Warren Spahn, Pittsburgh Steeler Rocky Bleier, and of course, Pat Tillman.

6. Only one American president has been awarded the Purple Heart. John F. Kennedy served in the Navy during World War II, and was injured when a Japanese destroyer collided with his patrol torpedo boat near the Solomon Islands. As his boat sank, Kennedy did not let a serious back injury stop him from towing a badly burned crew member to safety. Kennedy swam for more than three miles with the strap of the man’s life jacket in his teeth before reaching safety on an island.

The last president to see combat was George H. W. Bush.

7. The most Purple Hearts awarded to one person (so far) is 10.Curry T. Haynes, serving in the U.S. Army 173rd Airborne Brigade, Company C of the 503rd Infantry, arrived in Viet Nam in 1967. He was awarded his first Purple Heart after a jungle ambush during which he was shot in the arm. He returned to battle as soon as he recovered, and in the span of just one assault, sustained nine injuries, including losing two fingers. He later received nine more Purple Hearts, one for each wound.

In 2017, Haynes succumbed to cancer at the age of 72.