Up here Rocky used to make a lot if not all of their frames locally. But market pressures forced them to use the eastern shops years ago. Raceface still makes their CNC items in Canada from the labeling in them but from what I'm seeing a lot of their forged stuff is coming from offshore as well.
Places like Waterford and Rivendell (I assume these are US made?) and Gunnar and a few others will always be there but they will always be a minor niche corner of the industry because there just isn't that manyfolks willing to pay that sort of price. If you want a domestically made frame you'll have to go with one of those options. Up here we still have Marinoni which is a small order and custom shop based in eastern Canada.
So they ARE out there. YOu just need to find them and buy from them to justify keeping their doors open.