War Games In Gretna
by Vince Montano
[Originally published in the Fall 2026 issue of Mount Gretna Magazine. View the complete issue to experience this story in its original design, along with additional photographs and content.]
On the former Mount Gretna Military Reservation, the Pennsylvania National Guard trained and mustered for the Spanish-American War, the Mexican Border Campaign, and World War I. From 1885 until the 1930s, Gretna was their training grounds. It is accepted history that, as the United States approached World War II, the Guard’s training took place at its new home, Fort Indiantown Gap. By the end of the 1930s, the Gretna reservation had closed, its use as a training ground over.
Or was it?
My recent research into news archives and period publications of the Pennsylvania National Guard has cast new light on Gretna’s military history.
The Guard returns to its former home
On June 12, 1941, a foreign enemy landed on Delaware Bay, invaded the eastern United States, and advanced with armored units into Pennsylvania. With the 44th Division at Fort Dix, New Jersey, defending Philadelphia and Camden, it was up to the federalized National Guard’s 28th Infantry Division at Fort Indiantown Gap to defend the Commonwealth alone. They would make their stand on Gretna’s former training grounds.
Fortunately, for Gretna’s residents, the “enemy invasion” existed only in the fictional scenario created by 28th Division strategists. Maj. Gen. Edward Martin commanded a two-day “war games” exercise that would test the 28th Division’s ability to advance troops and weapons for war.
In the division’s largest mass movement of armed forces in more than two decades, 10,000 soldiers, carrying full fighting equipment, marched 20 miles from Fort Indiantown Gap to Gretna.
As three troop columns followed different routes, townspeople watched as regimental bands played marching music while soldiers passed through Ono, Bellegrove, Palmyra, Annville, Campbelltown, and Upper Lawn. Upon their arrival, field hospitals and kitchens stood among the 5,000 tents erected across six square miles of Gretna’s training grounds.
Pvt. Harry Kohr, whose son Karl resides in Cornwall today, lived in Miner’s Village and was a member of the Guard. He was here for the exercises and relieved to have avoided the long march by traveling to Gretna in one of the 1,600 military vehicles following the troops.
A “concealed bivouac” tested the troop’s ability to hide their tents from aerial view, while a 103rd Observation Squadron airplane evaluated whether the camps were visible to the “enemy.”
Communication networks were tested among brigades, the motorized column, Gretna, and Fort Indiantown Gap. Scouting patrols sought the “enemy” to their flanks and front. Officers’ tactics were evaluated, and soldiers’ physical condition was assessed. For the first time in the division’s history, soldiers operated as self-contained brigade combat teams, employing modern blitzkrieg tactics.
For area residents driving Route 117 between Gretna and Colebrook, one can only imagine the sight of thousands of soldiers, tents, and vehicles that may have been visible from the roadway.
At a press conference in Gretna, Gen. Martin expressed his satisfaction: “The maneuver could not have been more successful… I am very much impressed with the high morale of the men and the willingness of each individual to do his part… The men are in marvelous physical condition.”
July 1941 brought one final “war game” to Gretna when the 28th Division Headquarters, Special Troops, and all Brigade Headquarters in the division held Command Post Exercises. During this “invasion,” officers became acquainted with an increasingly important phase of modern warfare: air-to-ground communications. The 28th Division Signal Corps coordinated radio messages with three reconnaissance airplanes from the 103rd Observation Squadron photographing “enemy positions.”
Two hours later, individuals delivered the finished photographs to the command post. A pilot, Capt. George E. DeCoursey, directed troop movements via radio and dropped messages, notifying ground forces that “invaders” would attempt to break through defense lines at Colebrook. Troops received orders to defend Colebrook and hold off the “enemy.”
Soldiers with the 108th Field Artillery, armed with huge howitzer cannons, moved their guns into firing positions. While no one fired these 5-ton artillery weapons, the guns were sighted and serviced as if operating under wartime conditions in unfamiliar territory.
During these mock battles, umpires supervised the exercises and prepared intelligence reports. Commanders and their officers planned missions using maps and theoretical attacks, synchronizing war-fighting functions, and demonstrating the ability to make quick, effective decisions under pressure. These command-and-control exercises tested internal operations, communications installations, and information flow. Simulated battle scenarios included a “night problem” and a plan to go on the offensive and drive back the “invaders” from Colebrook.
Gen. Martin concluded, “This maneuver is just like a football game. Every man must know his position and must play his part… Every detail had been very capably taken care of. That’s what I call real organization!”
Pennsylvania’s 28th Division goes to war
Four months later, the enemy invasion became real when the Japanese attack on Pearl Harbor, Hawaii, drew the United States into World War II. The 28th Infantry Division served with distinction in Normandy, Northern France, Rhineland, and Central Europe. They were instrumental in halting the German advance at the Battle of the Bulge by constructing bridges for the Allied advance through Europe and assisting with the liberation of Paris.
In the shadow of Gretna’s once grand and former military encampment, the 28th Infantry Division held its largest training maneuvers since World War I at Gretna, honing the skills to advance the Allied victory over Germany and broadening our view of Gretna’s storied military past.
In that summer of 1941, the Mount Gretna Military Reservation served the nation, one last time, preparing the men of Pennsylvania’s armed forces for the greatest war the world would ever know.
Vince Montano lives in Cornwall and is a historian, writer, and avid hiker. He’s been exploring Mount Gretna and its history for more than 30 years and loves discovering ruins throughout the surrounding area from Gretna’s National Guard days. He is a contributing member of the Mount Gretna Area Historical Society.
