STI, Infinity, Briley, High Standard, AMT (owned by High Standard, so I do not know if they count), Interarms (also owned by High Standard). I think Maverick 88 shotguns are made somewhere around here

Hmm, I got nothin'. Closest would be Alberta Tactical Rifle one province over. Every other manufacturer in Canada seems to be in Ontario.

AMT was founded in California and their guns are stamped as such, I don't think I've seen one of their guns with Texas marked on it.

http://www.highstandard.com/brands/amt-automag.html

Ah, I found one stamped Texas too, that's pretty cool. Kinda sucks that they decided to continue making their lamest product line, though the .22 Automag looks pretty cool.

Beretta USA in Accokeek, Maryland

I believe Ruger makes their new autoloaders here in NH.

Just freedom arms for wyoming.