The Pennsylvania National Guard traces its lineage back to the militia organized by Benjamin Franklin in 1747 known as the Associators.

The first meeting of the Associators occurred on 21 November 1747, and on 7 Dec. 1747, the enlistees and officers were formally commissioned by the Provincial Council President, Anthony Palmer.

In 1793, the Governor of Pennsylvania, Thomas Mifflin established the Adjutant General's Office to provide for "a new system for the regulation of the militia."

The next year, Pennsylvania contributed 4,000 militiamen to a four-state force which quelled the Whiskey Rebellion in the western part of the state.

Before the Battle of Lake Erie, an artillery company provided volunteers to serve as cannoneers aboard Commodore Perry's ships.

At the start of the American Civil War in April 1861, five units from the Lehigh Valley raced to Washington, D.C., which was under threat, in response to an urgent plea from Congress.

[4] President Lincoln proclaimed them the "First Defenders"—an honor still borne by their descendants in varied PA National Guard units.

When the United States Army created the Spanish War Service and Mexican Border Service Medals, Major General Charles M. Clement was designated as the first official recipient of each, in recognition of his status as the longest-tenured National Guard officer eligible for the medals at the time they were authorized.

Clement served in the Pennsylvania National Guard from 1877 to 1917, and commanded the 28th Infantry Division at the start of World War I.

Among the units formed after the end of World War II reorganization of the National Guard was the 628th Tank Battalion.

In June 1959 the Pennsylvania Army National Guard was extensively reorganized in line with the Pentomic (ROCID) organization then coming into force.

[13] At that time, a number of separate Tank and Field Artillery Battalions which had served through World Wars I and II were reorganized as regiments.

1-176 and 2-176 were part of the 218 AG(AD) from 1 June 1959 to 1 Apr 1963, after which the 2-176 joined the 213th Artillery Group (Air Defense) until 17 February 1968, and thereafter until 1974 just with the PA ARNG.

[12] Nearly 13,000 Army and Air Guard members were called to state active duty to help with relief operations.

[17] After the Iraqi invasion of Kuwait in August 1990, eight Army and Air Guard units from Pennsylvania[12] (seemingly including the 228th Transportation Det, the 121st and 131st Transportation Companies, the 28th Finance Unit, and the 3623rd Maintenance Company)[18][19] were mobilized for duty during Operations Desert Shield and Desert Storm.

In 1996, Pennsylvania Guard members opened roads, transported doctors and patients, and mounted dangerous helicopter rescue operations during statewide flooding and blizzards.

The Philadelphia Daily News reported that the 103rd Engineer Battalion had helped clear roads in the city, in conjunction with the Pennsylvania Department of Transportation.

Under permanent order #051-02 dated February 20, 2016, elements of the 165th Military Police Battalion began to be established, reforming a unit seemingly last active in 1989.