The use of 5-tonne trucks for material transport and with special superstructures has a long tradition in the U.S. Army. Since its introduction in 1982, the M939 truck family has been the backbone of the American transport fleet in all theatres of operation around the world. This publication provides a comprehensive and complete history of the development of this unique design, from the prototypes to the latest variants, from the flat/platform version to the special vehicles and armoured variants. This closes another gap in the history of modern American military trucks.