Happy birthday to the Army National Guard! On December 13, 1636, the militia that gathered in Boston, Massachusetts officially established America’s oldest fighting force.

In honor of their birthday today, here are five quick facts about the Army National Guard:

1. After the 9/11 attacks in 2001, 50,000 members of the National Guard took on various missions.

2. During the American Revolution, National Guard members were called “Minutemen” because of their quick ability to respond.

3. Two U.S. presidents served in the National Guard, Harry S. Truman and George W. Bush

4. Since December 13, 1636, National Guard members have fought in every war.

5. The National Guard comes in second to the U.S. Army in terms of most number of members.

Thank you for all of your hard work and sacrifice, Army National Guard! Happy birthday!