On Thursday, December 13, 2018, the United States National Guard will celebrate its 382nd birthday, making it 140 years older than the nation it protects.

Today, the reserve military force represents a joint effort on the part of two branches, the United States Army and Air Force. The Army National Guard and Air National Guard are garrisoned in all 50 states, as well as the District of Columbia and the territories of Guam, Puerto Rico and the Virgin Islands.

There's been quite a bit of history since the first militia organized in 1636, and this anniversary presents the perfect opportunity to reflect on the nearly four centuries during which the Guard has been "Always Ready, Always There!"

"The appearance of U.S. Department of Defense (DoD) visual information does not imply or constitute DoD endorsement.""The appearance of U.S. Department of Defense (DoD) visual information does not imply or constitute DoD endorsement."

The history of the U.S. National Guard

Militia forces were first mustered in what is now the United States as early as 1565, when Spanish settlers in St. Augustine were tasked with guarding supplies during the onset of a hurricane, while regular troops were up north attacking a French settlement on the St. Johns River. In the early 1600s, militias were mustered in the New World's first permanent English settlements of Jamestown Colony and Plymouth Colony, which originally consisted of all able-bodied adult men.

However, according to the Department of Defense, the official birthdate of the National Guard took place on December 13, 1636, when the Massachusetts colonial legislature officially directed the colony's existing militia companies to be organized into three regiments. Today, the four descendants of that initial trio of regiments — the 101st Engineer Battalion, the 101st Field Artillery Regiment, the 181st Infantry Regiment, and the 182nd Infantry Regiment, all of the Massachusetts Army National Guard — hold the distinction of being the oldest units in the United States military.

It may seem strange to some that the National Guard is older than the U.S. Army, but that position is based on the Militia Act of May 8, 1792, which permitted already extant militia units to retain their "customary privileges."

In 1903, passage of the Dick Act required states to divide their militias into two sections, recommending the titles "Reserve Militia" and "National Guard." The passage of the National Guard Mobilization Act in 1933 fully codified the division between traditional state militias and the National Guard, mandating that all federally funded soldiers take a dual enlistment in both the state National Guard and the newly created National Guard of the United States.

The history of the Air National Guard

Following World War II, the Truman administration pushed for a major restructuring of the nation's military and intelligence agencies, which led to the passage of the National Defense Act of 1947. Among other things, this legislation created the Air Force as a separate branch of the Armed Forces, which consequently formed the Air National Guard of the United States as a unique entity separate from the Army National Guard.

And yet, the oldest unit in the Air National Guard actually predates the institution itself by over 30 years.

On November 22, 1915, the 102nd Rescue Squadron of the New York Air National Guard was organized in accordance with existing law and authorized in the New York National Guard as the Aero Company, Signal Corps. However, the oldest Air National Guard unit that has remained in continuous existence since it was first federally recognized is the 109th Airlift Squadron of the Minnesota Air National Guard, which originated as the 109th Observation Squadron on January 17, 1921.

All of the state, territory and District of Columbia militias that collectively form today's Army National Guard and Air National Guard trace their heritage back to those first three regiments organized at the direction of the Massachusetts colonial legislature on December 13, 1636. While the Guard may not literally have been "Always There" throughout time immemorial, at 382 years of age, they come pretty close.