What was not mentioned in this thread is a fundamental difference in the market. In general:
1) The "big" bicycle brands sold at all local bike shops (LBS) and their dog**** counterparts at the mass merchant are all made overseas. Frames & components made abroad, the vast majority in Asia. This is the current reality of the global marketplace. Where 20 years ago there was a smattering of US-made frames by the big brands, you still had foreign components. So in the end, only ONE thing on the bike was US-made, the frame. Trek and Cannondale were the last of the "big" makers to finally move everything overseas.
2) The actual "made in USA" bikes are almost always made in USA FRAMES. And these tend to be small production local framebuilders. All the rest of the components are usually sourced from overseas as well. But not all. Many of the high-end bikes have US-made components from the brands listed. There are some larger producers here (Litespeed), but they're a small segment.
3) A FULLY-MADE IN USA bicycle, top to bottom, stem to stern is a very, VERY RARE THING. As the last poster indicated, it would be a fun endeavor AND expensive.

So your choices are this:
Foreign-made bikes of all flavors and prices. The killer $12k Yeti full suspension rig and the $75 WalFart bike are made in Asia (for most intents and purposes). This is what 99% of the American public purchase. There are really awesome bikes and then there are the not-so-awesome bikes (showing restraint, not sure why!).

Boutique bikes made by American framebuilders. They are a thing to behold. Beautiful. Collectors items. Something to ride for a lifetime. But along with this comes high price and oftentimes a long wait. But it can be worth it.

So I hope that helps put things into perspective.