Their are hundres of tanks that have been made by the US, but the time with the most intereting tanks was World War II. Take for example M4 Sherman which was a take that was mass produced for the US forces, but sadly for the tank it had weak ammor compaired to their German enemys. Because the germans had heaviy tanks like the Tiger 1 or Tiger II . They were both the most heaivy and dangerous on the Westtern fronts for the American tanks. With the Germans tanks 88mm canons that could easly eat through and Sherman armer. Plus the lowly 75mm cannon for the M4 could only penitrate the side armor of any German tanks, so if any head on combatt had happened the M4 would be domolished. Luckly the American engenears had notised and had started the production of the M26 Pershing . This tank was a 76mm high pouder lode cannon and heaivy armor came in to action neer the end of the war.This tank was slowly chaching up with German engenering, but with the war's end near this tank was not used to it's full uses.