OSHpark is the most common company for hobbyists, but they aren't actually a manufacturer. Typically the reason most hobbyists use overseas board houses is that US board houses typically have large minimum order requirements. What OSH does is take projects from a bunch of people and organize them into one large order that's big enough for the US manufacturer to take it. As I understand it there are twoor three board houses they typically send to, but I wasn't able to figure out which ones. OSH is a reasonable option for small batches, but for larger runs they just don't make sense in my opinion, their prices are nowhere near competing with overseas manufacturers like JLCPCB or Elecrow.
The only USA house I've really looked at seriously was
Advanced Circuits and their prices are just too high to make them viable for me. A board that would cost me less than $1 per PCB overseas costs anywhere from $65 (5 qty) to $5 (150 qty) per PCB from Advanced Circuits. Also most overseas houses will do electrical testing at no additional charge, but Advanced charges an extra $175 per batch to do the same testing.
I will say that one benefit to USA board houses is that if you're in a hurry many houses will negotiate same-day runs if needed, unlike a typical
PCB manufacturer setup in overseas production. It would be expensive, but if there's a board house within driving distance from you (worth a search, there are a couple within range of me) and you have special circumstances requiring it, you could place an order in the morning and pick it up in the afternoon. I doubt anyone would have urgent stompbox needs, but something to consider if your circumstances require it.
