I have no idea where all of the components are made - never thought to ask. I'm sure some components are imported, of course. As BloggingITGuy points out, it's mighty hard to avoid. Components like transistors are very likely manufactured overseas (some info on the old ATI 1505 and Outlaw 750 indicated that both used Toshiba transistors, for example, and I doubt that Toshiba has much US manufacturing capacity). Based on what I've heard about ATI, though, a lot of it is of domestic manufacture. Details on their manufacturing process are fairly scarce from a consumer perspective, but I did find one quote here that matches what I've believed to be the case for ATI's operation:

If they're winding the transformers and manufacturing the circuit boards on-site in addition to doing the actual assembly, there's not a lot other big stuff left. Are the aluminum heat sinks and faceplates machined domestically? No idea - certainly possible, but not guaranteed.