M18 GMC 76mm Tank Destroyer
Tank vs Tank Destroyer was a concept developed as an attempt to stop Blitzkreig style tactics seen early in the war. US Army planners saw the tank as an infantry support vehicle with machine guns and dual purpose artillery style cannon. When armor protection steadily inproved the need for a tank killing capability arose and the planners figured a light weight vehicle with a higher velocity gun could be moved quickly in place to stop an armored penetration. The M10, M18, and M36 were developed as the face of that plan and the debate over their effectiveness and utility has raged ever since.