Photograph of Martin MB-1 mail plane
Martin MB-1 Mail plane, tail number 202 parked at an unknown airfield. The MB-1 was a bomber designed by Glenn L. Martin. It was designed for the US Government with the goal of outperforming the British Handley Page. The design never saw service in the war, however, a number of the bombers were acquired and used by the Post Office Department.
Courtesy of the National Air and Space Museum