That's a big question Ted and I can't fully answer it. But some thoughts: It wasn't just Connecticut in the sense that all these northeastern states developed their own manufacturing specializations. Worcester Mass in wire; Holyoke Mass in paper; Rhode Island in jewelry and toys, etc. In regard to brass, CT happened to have low grade ores to start with (probably smelted by charcoal initially) but once the labor pool and machinery were in place, in a way, the ores didn't matter anymore. Eventually many parts were stamped out, not smelted, so since you could make 50,000 brass triggers or 100,000 clock gears (I'm guessing numbers of course) from a railroad car full of brass plate it didn't matter if it had to be shipped in from the Mesabi Range. Skilled labor was the resource that mattered, not volumes of raw material or fuel. Very much the opposite was the steel industry that was ALL about volume and weight of raw material and finished product. That being said, after the Civil War, coal was everywhere in the northeast via rail and so were ores. So you could do some smelting in CT if you wanted to.