The M103 heavy tank reflected the design trends of the post-World War II US Army and, although it was the least developed of all the US tank programs of the time, the outbreak of war in Korea brought a rush order for 300 vehicles. Evolving Army design criteria, however, meant that, were it not for the Marine Corps investing its scarce funds in continued support of the heavy tank program, these vehicles would have languished in storage before their eventual disposal. Thanks to the Marine Corps' faith, essential imporvements were made and, by the time the M103 was retired, tis years of operational service had demonstrated the soundness of its engineering. It may have been the unwanted 'ugly duckling' of the Army, but before the era of anti-tank missiles it was the only weapon system that could face the Soviet heavy tanks on largely equal terms, and the Army evenutally realized this, borrowing 72 from the Marines for use in their deterrence mission in West Germany.

Machine generated contents note: Developing the T43 Heavy Tank, 1948-55 -- Initial Progress to 1950: Design and Specifications of a Heavy Tank -- War and the Tank Crash Program, 1950-54 -- Engineering and Producing the T43 Heavy Tank -- Delivering the M103 Heavy Tank -- Bringing the Project to Completion: the Marine Corps M103A1 -- The M103 Series Heavy Tank in Service -- The Marine Corps Heavy Tank Enters Service -- Heavy Tanks in the Fleet Marine Force -- One Last Modification: M103A2 -- Operating the M103A2 -- Other Variants in Service.