The 28th "Keystone Division is the oldest Division in the armed forces of the United States. On November 30, 1953, the Office of the Chief of Military History certified that General Order No. 1, March 12, 1879, officially established the Division.

Revolutionary War Days. Elements of the Division can trace their histories back to 1747, when Benjamin Franklin organized his battalion of "Associators" in Philadelphia. Other Pennsylvania units of the 28th Infantry Division had their beginnings in the Revolutionary War. Troop A, 1st Squadron, 104th Cavalry, was organized November 17, 1774. The 109th Artillery Regiment was formed October 17, 1775, as the 24 Connecticut Militia. Both units served with distinction in General George Washington's Continental Army during the war.

The 19th Century. During the War of 1812, the Mexican War and the Civil War, units fought victoriously at Vera Cruz and Cerro Cordo. Units of the Pennsylvania Militia won 29 battle streamers during these wars. In 1878, Governor John F. Hartranft conceived the idea of forming a single National Guard of Pennsylvania. Hartranft became the 28th Division's first commander. The Division was mustered into federal service in 1898 for the Spanish-American War. Elements saw action in Puerto Rico and the Philippines. On October 27, 1918, the red keystone was designated the shoulder sleeve insignia of the Division. The distinctive keystone was the second shoulder sleeve patch to receive official Army approval.

World War I. Units of the 28th Infantry Division, known at the time as the 7th Division, were called to active duty for the Mexican Border incidents in 1916. Pennsylvania's 7th Division was ordered to active duty at Camp Hancock, Georgia, on July 15, 1917. On October 11, 1917, the Division was reorganized as the 28th Division while they were still training in Georgia. The 28th Division arrived in France May 18, 1918. It was committed to battle on July 14, 1918. Soldiers of the Division participated in six major campaigns - Champagne, Champagne-Marne, Aisne-Marne, Oise-Marne, Lorraine and Meuse-Argonne. During those campaigns, over 14,000 battle casualties were suffered by the Division. Their fierce combat abilities earned them the title "Iron Division" from General of the Armies, John J. Pershing.

World War II. The Division was reorganized soon after deactivation in 1919. On February 17, 1941, the 28th Division was ordered into federal service for one year of active duty. With the Japanese attack on Pearl Harbor on December 7, 1941, the Division remained on active duty for the duration of the war. The Division sailed for England in October 1943. On July 22, 1944, the 28th Division landed on the beaches of Normandy. It fought through Normandy, across Western France, to join in the liberation of Paris. The famous picture of American troops marching down the Champs Elysee shows the men of the 28th Division. The day following the parade, the Division soldiers moved on to fight in some of the bloodiest battles of the war. It fought in the Huertgen Forest, distinguished itself in the Battle of the Bulge and the Colmar Pocket. The 28th "Keystone" Division earned the title of the "Bloody Bucket" Division from the German Army.

With the end of the war in Japan, the Division was deactivated December 13, 1945. Five campaign streamers - Normandy, Northern France, Ardennes-Alsace, Rhineland and Central Europe - were earned during World War II. The 28th was also awarded the Croix de Guerre.

Korea to the Mid '60's. Early in 1946, the 28th "Keystone" Division was organized as part of the Pennsylvania National Guard. In July 1949, the North Koreans invaded South Korea and the Division was once again ordered into active service to become part of the United States' NATO force. Though most of the soldiers were returned to the United States by June 1952, the Division was not returned to the control of the commonwealth until June 15, 1954.

The Vietnam War. In October 1965, the 28th Infantry Division was one of three National Guard Divisions selected as part of the Army Selected Reserve Force. In 1968, as part of the SRF and high on the list for activation, it was again reorganized into a three-state configuration.

Recent Times. Since 1870, thousands of 28th "Keystone" Division soldiers have served the commonwealth in a variety of civil defense and natural disaster roles. The 28th was involved in civil missions including: providing security during tropical storms Agnes and Eloise in 1972 and 1975, evacuation planning during the Three Mile Island nuclear reactor emergency in 1979, patrol and escort aids during the trucker's strike of 1974, and conducting water purification operations after a 1988 oil spill in the Monongehela River. During Operation Desert Shield and Desert Storm, Division volunteers served as members of other Pennsylvania National Guard units mobilized and deployed to the Persian Gulf.

The Department of the Army realigned the 28th into a single-state division April 1, 1975. This decision brought all the troops back to Pennsylvania. During Annual Training in 1978, the Division developed an extremely useful training relationship with Active Army divisions. In 1988, the Division began a training partnership with the 24th Infantry Division (Mechanized). Effective October 1, 1988, the Division was placed under the control of the XVIII Airborne Corps in Fort Bragg, North Carolina.