What classes of submarines did we build during the war?

The first of the newest WW2 classes, the Gato boats, were just being commissioned when the Japanese attacked Pearl Harbor. The design had been set in 1939 and then we started building this new class. This class, plus the Balao and Tench classes, were what we built during the war. All three classes were very similar, other than the thickness of the hull, and look the same to most observers. Sometimes all three classes are referred to as Gato boats.

The Balao class boats had a thicker hull, at 7/8 inch rather than 11/16 inch for the Gatos.The hull was also strengthened to allow the boat to sit on the bottom. The Tench class kept those improvements and had some ballast tank piping rerouted for safety. 

We completed a total of about 77 Gato class, 119 Balao class and 25 Tench class boats during and shortly after the war.