Constituted as 73d Observation Group on 21 Aug 1941. Activated on 1 Sep 1941. Engaged in training activities, participating in the Tennessee Manoeuvres in 1943. Redesignated 73d Reconnaissance Group in Apr 1943, 73d Tactical Reconnaissance Group in Aug 1943, and 10th Photographic Group (Reconnaissance) in Dec 1943. Moved to the European theater, Jan-Feb 1944, for duty with Ninth AF. Used F-3, F-5, F-6, L-I, L-4, and L-5 aircraft for operations, Feb1944-May 1945. Photographed airfields, coastal defences, and ports, and made bomb-damage assessment photographs of airfields, marshalling yards, bridges, and other targets, in preparation for the Normandy invasion; received a DUC for flying at low altitude to photograph the coast from Blankenberghe to Dunkirk and from Le Touquet to St- Vaast-la-Hougue, 6-20 May 1944.
Supported the invasion in Jun by making visual and photographic reconnaissance of bridges, artillery, road and railroad junctions, traffic centers, airfields, and other targets. Assisted the Allied drive toward the German border during the summer and early fall of 1944 by flying daylight and night photographic missions; also performed tactical reconnaissance for ground and air units, directing artillery to enemy positions and -fighter-bombers to opportune targets. Aided Third Army and other Allied organisations in the bat- tle to breach the Siegfried Line, Sep-Dec 1944. Participated in the Battle of the Bulge, Dec 1944-Jan 1945, by flying reconnaissance missions in the combat zone. From Feb 1945 to V-E Day, assisted the advance of Third Army across the Rhine, to Czechoslovakia, and into Austria. Remained in Germany after the war as part of the army of occupation, being assigned to United States Air Forces in Europe. Redesignated 10th Reconnaissance Group in Jun 1945.