But its history is long and distinguished: the National Guard has been a pillar of support for the other branches of the armed forces as well as an active protector on our home soil.
In honor of the National Guard's birthday, here are some lesser-known facts about the branch.
1. Each member of the National Guard is sworn to uphold two constitutions: federal and state.
2. The term "national guard" was popularized by Marquis de Lafayette to describe each state's militia. It didn't become an official term until 1916.
3. 50,000 members of the National Guard were called to take on various missions during the 9/11 attacks in 2001.
4. Only two presidents have served in the National Guard in its modern structure: Harry S. Truman and George W. Bush.
5. The National Guard is older than the Army. Militias were used as early as 1636 to protect British colonies. The U.S. Army wasn't formed until the beginning of the Revolutionary War.
6. American Samoa is the only territory of the U.S. to not have a National Guard unit.
7. National Guard units were called Minutemen during the American Revolution due to their rapid response ability.
8. The most senior member of each state National Guard unit is the Adjutant General. Some states elect the Adjutant General, while others have their Governor appoint someone to the position.
9. The National Guard formed one of the first all African American units in U.S. military history, the 54th Massachusetts Volunteers. Their creation was met with mixed reactions, but the unit serves to this day and the first African American to receive a Medal of Honor, William Harvey Carney, hailed from it.
10. The National Guard is second only to the U.S. Army in terms of number of members.