A happy 387th birthday to the oldest component of the U.S. military: the National Guard.

The National Guard recognizes Dec. 13, 1636, as its official birthday. On this day, the militia of what was then the Massachusetts Bay Colony was organized into three permanent regiments. The descendants of those regiments are today known as the 101st Engineer Battalion, the 101st Field Artillery Regiment, the 181st Infantry Regiment and the 182nd Infantry Regiment of the Massachusetts Army National Guard, and are recognized as the oldest units in the U.S. military, according to a National Guard fact sheet.

The West Virginia National Guard celebrates the 387th birthday of the National Guard at Joint Forces Headquarters in Charleston, W.Va., Dec. 13, 2023. More than 100 members of the Guard, civilian employees and special guests attended a ceremony marking the birthday, which included presentations on the history of the National Guard, remarks from Guard leadership and a ceremonial cake cutting lead by Maj. Gen. Bill Crane, adjutant general. (Zoe Morris/U.S. Army National Guard)

How can the National Guard be older than the Army — or indeed the U.S. itself? The Militia Act of May 8, 1792, provided for the organization of state militia and allowed the U.S. president to take command of these militias in times of invasion or insurrection. But the act also allowed militias organized before the enactment to retain their “customary privileges,” according to the National Guard — hence, the National Guard officially began with the organization of Massachusetts’ militia.

These state militias officially became the modern National Guard with the passage of the Militia Act of 1903, which codified circumstances under which the Guard could be federalized.

The Air National Guard officially became a reserve component of the U.S. Air Force on Sept. 18, 1947, when the National Security Act of 1947 created the Air Force.

Today, more than 325,000 soldiers and 106,000 airmen across 50 states, three territories and the District of Columbia serve in the National Guard, according to the service.

U.S. Army Maj. Gen. Thomas Carden, the adjutant general of the Georgia National Guard, cuts the cake along with the soldier and airman of the year, Staff Sgt. James Varley and Senior Airman Brittney Santos, during the 387th National Guard birthday ceremony Dec. 13, 2023, at the Clay National Guard Center in Marietta, Ga. (Georgia National Guard)

New York Army National Guard Pvt. Sean McCauley, age 17, joins Chief Warrant Officer 5 Mark Shumway, the New York Army National Guard command chief warrant officer, and Chief Warrant Officer 5 Michael Zanghi, age 60, in cutting the National Guard birthday cake during a ceremony marking the 387th anniversary of the National Guard on Dec. 13, 2023, at New York National Guard headquarters in Latham, N.Y. McCauley, who enlisted in July and was the youngest Guardsman present, represented the future of the National Guard, while Zanghi, who retires in February 2024 represented the history and traditions of the Guard. Shumway served as the presiding officer for the ceremony. (William Albrecht/New York Army National Guard)