This is an old thread, but as far as I know the classic reciprocating compressors are still built in Quincy Illinois, at 3501 Wisman Lane (217) 277-0343. Since the 1960s the ownership of the company changed at least twice. I was born in Quincy. I'm not sure whether all the components are US made anymore. I think the Id plate will state whether the compressor was manufactured and shipped from Quincy Ill, or Bay Minette Alabama.