Ramshot and Accurate (both divisions of Western Powder) don't MAKE anything. They are packagers and distributors.
TAC is made in Belgium and I think many if not all the other Ramshots are, too.
AA has contracted powder from all over the world but is now buying American, undoubtedly from St Marks, the only US maker of Ball powders. I really want current AA data because the powders have changed while the labels have not.
C.E. Harris, mentioned above, says the big shift in IMR powders was when production shifted from the US to Canada in 1976.
I have a few facts and a lot of opinions.