The group was organized on 29 June 1918 at Gengault Aerodrome, Toul, France, initially consisting of the 22d Aero Squadron. The 2d Pursuit Group immediately began operations against the enemy. The 139th Aero Squadron was assigned to the group the next day, and by 15 August the 13th Aero and 40th Aero filled out the unit's compliment of squadrons. All of the squadrons were equipped with French SPAD XIIIs. In theory the group totaled 72 aircraft and an equal number of pilots. The reality was that it was rare for the number of pilots to equal the number of aircraft or for the aircraft to be fully standardized across an entire group.
When the armistice was signed and hostilities ceased at 11:00 11 November, the pilots of the group had flown 7,788:21 hours in combat over enemy territory. In the 111 flying days made possible by the weather, 358 pilots engaged the enemy in 166 air combat battles with the loss of 30 pilots. Of the 166th air battles, 132 victories were officially credited to the pilots of the group, with 16 "Air Aces" with five or more enemy aircraft to their credit. In addition, four pilots of the group were decorated with the Distinguished Service Cross.
^ abcdefSeries "C"; Volume 10, History of the 2d Pursuit Group, Gorrell's History of the American Expeditionary Forces Air Service, 1917-1919, National Archives, Washington, D.C. via http://www.fold3.com