You can get a new Trek 1000, Giant OCR-3 or any number of other good bikes in that price range. My first road bike was a Trek 1000. At that point I weighed about 230# and had no problems with it. The main advantage of buying one of these bikes over a bike from the internet is customer service. You can work with the LBS to make sure the fit is just right. Check out the Under $750 thread on the Road Forum.
I am, onthe other hand, fairly certain that no one makes frames in that price range in the U.S. anymore. No one makes components, except wheels, in any price range here anymore, and haven't for years.
I don't know if there were ever any derailleurs made in the U.S.. There probably were, but finding them would be very difficult. So the bottom line is there is no such thing as a bike made in America.
Cannondale puts big stickers on their bikes saying "Handmade in the U.S.A.". That means "part of this bike was made in the U.S.A. with materials from other countries, but was mostly made in China and put together in America by people who are from another country."
Get over it and buy the bike you like the best.