In celebration of Veterans Day, check out these facts you may have never heard before.

1. November 11 was originally called Armistice Day, and was set aside to honor veterans of World War I. The date became a national holiday in 1938. Congress changed it to Veterans Day in 1954, and decreed that it would celebrate veterans of all wars.

2. World War I ended 91 years ago, in 1918, and only one American soldier is still alive, according to the Department of Veterans Affairs. His name is Frank Woodruff Buckles, born in 1901 in Missouri. He went on to also serve in World War II, where he was captured by the Japanese and spent three years in a prison camp before being rescued. The last surviving female WWI veteran died in 2007. She lived to be 109 years old, and was buried with full military honors.

3. What they were fighting for: Frederick’s of Hollywood, the pioneer of eye-popping ladies’ underwear, was founded by World War II veteran Frederick Mellinger. He started the company as a mail-order business in 1946, and based his line of lingerie on what his Army buddies had told him their girlfriends would like – or maybe on what they wanted their girlfriends to like!

4. Over fifty years after the fighting officially ended, 8,176 Korean War troops are still officially listed as missing in action.

5. The haunting Vietnam Veterans Memorial was first proposed by Jan Scruggs, a 29-year-old Vietnam veteran from Bowie, Md. He began a fund-raising campaign for the memorial in May 1979, using $2,800 of his own money.