Developed by General Aviation (the precursor of North American Aviation) to meet a US Army specification for an observation aircraft, the GA-15 represented a radical change in design for such a role in that, unlike its predecessors, it was a low-wing monoplane with an enclosed cockpit, seating a three-man crew. Powered by a 634kW Wright Cyclone engine, the prototype flew in mid-1935 and to provide an acceptable field of view for the observer a glazed nose position was located under the fuselage. North American put the type into production to meet a USAAC contract for 109 North American O-47A aircraft ordered in February 1937, later increased to 164. They were powered by 727kW Cyclones, while 74 O-47B aircraft had 790kW engines and additional fuel capacity. During World War II they served as trainers and target tugs.