A successor force for New Ironsides

Could the United States have built improved New Ironsides successors for coastal defense and overseas diplomacy?

Yes industrially, but pre-Mahan politics and an inward-looking strategic outlook made congressional support for such a force doubtful.

The proposal calls for four to six longer, faster successors to New Ironsides, each carrying roughly 20 to 24 guns and Gatling guns against spar-torpedo attackers. This force would combine deep-water coastal defence with gunboat diplomacy in Central and South America, then provide a base for later naval expansion. The answer accepts that American industry could build such a class. Congressional support was the harder problem because the proposal came before Mahan's ideas gained political influence and before the United States consistently imagined itself as a world-spanning naval power.