The P-47 Thunderbolt was considered a rugged aircraft that was excellent at ground attacks. Weighing nearly 7 tons with thick armor plating and a heavily-armored engine, the P-47 could withstand massive damage from anti-aircraft guns. It was also useful in air-to-air combat fighting, but was most famous for its ground attack capability. The addition of droppable fuel tanks enabled the plane to escort bombers from bases in England to Berlin, Germany and back to England.

On March 13, 1944 the 406th Fighter Group was moved to Camp Shanks, Port of Embarkation, near New York City. The 406th Fighter Group boarded the HMT Starling Castle on March 22, 1944 for Liverpool, England arriving on April 4, 1944. The Group then proceeded to Ashford, Kent near Dover, England. The Fighter Groups first mission came on May 9, 1944 that was a fighter sweep over northern France. During the next three days the Fighter Group continued to conduct sweeps over France. During these sweeps they did not encounter any enemy aircraft or anti-aircraft fire.

On May 13, 1944, the Fighter Group received its first assignment to escort 36 B-26 Marauder Bombers to bomb a number of gun revetments near Abbeville, France. All bombers and fighters returned from the bombing mission without any incident. During the rest of May 1944 the Fighter Group participated in a wide variety of sweeps, bombing missions, and escorting bombers throughout France and Germany. During this time missions were increased to four to five a day to soften up areas in France along the English Channel. Marion Benson participated in these missions.

On June 6, 1944 the Fighter Group began providing air cover over the entire Normandy invasion area. Flights were arranged so that the 406th Fighter Group maintained the air cover 24 hours a day. Once the beach heads on Normandy, France were secured, the Fighter Group was order to focus all of its missions on various ground installations, bridges, communications centers, and trains to cause havoc within the German Army and assist the Allied Forces in making forward progress throughout Normandy.

During a mission attacking German ground installations in France on June 17, 1944, Lt. Marion Benson was critically wounded and his P-47 Thunderbolt was badly damaged by anti-aircraft fire. Since he was so critically wounded and his plane so badly damaged, Marion plunged his plane into one of the German anti-aircraft installations. For this action Lt. Benson was awarded the Distinguished Service Cross. The Distinguished Service Cross is the Army's second highest award for valor. The Congressional Medal of Honor is the Army's highest award for valor. A synopsis of Marion Arnold Benson's Distinguished Service Cross Citation is as follows: "The President of the United States takes pride in presenting the Distinguished Service Cross (Posthumously) to Marion Arnold Benson (0-806035), First Lieutenant (Air Corps), U. S. Army Air Forces, for extraordinary heroism in connection with military operations against an armed enemy while serving as a Pilot of a P-47 Fighter Airplane in the 514th Fighter Squadron, 406th Fighter-Bomber Group, 9th Air Force, in aerial combat against enemy forces on 17 June 1944, in support of Allied ground forces following the landings at Normandy, France. On this date, in aerial engagement, First Lieutenant Benson's fighter was badly damaged and he himself was critically wounded. With little hope for survival otherwise, Lieutenant Benson dove his falling fighter plane into a German gun position, sacrificing his life to destroy an enemy strongpoint. The personal courage and devotion to duty displayed by First Lieutenant Benson on this occasion, at the cost of his life, have upheld the highest traditions of the military service and reflect great credit upon himself, the 9th Air Force, and the United States Army Air Force." Information obtained from the American Battle Monuments Commission shows that Marion is buried at Plot J, Row 11, Grave 14, at the Brittany American Cemetery, St. James, France.