Benjamin Franklin once said that "North America has no mines". Which was rather silly of him, because it actually did. However, I’m telling you this to show you that there weren’t very MANY mines. The cost of transport and the vast distances over which mined ore had to be carried discouraged anyone but the most enterprising (and given the amount of work the average Colonist had to do from day-to-day, you’d frankly have to be very enterprising or very desperate.)
However, during the Revolutionary War, imports of metal were scarce – and sort of necessary for basic tools (like guns), so mining as an industry picked up. Most mines were used to dig copper and iron. Miners worked in extremely difficult conditions, often under the threat of raids from the local Indigenous peoples. They were usually low-wage foreign workers with few other employment options. So, desperate then.