the US that killed Concorde (some 30 years ago).

I think you're talking about the restriction on supersonic flight over land? As I remember, that had nothing to do with the Concorde, but rather, with the military. In the 1960s, it was common for military craft to travel at supersonic speeds over populated areas. We had to have everything on shelves wired up, our windows were constantly breaking. After that legislation, we only had to wire our nicknacks and repair windows because of earthquakes.

The Boeing SST's target market was the us / asia travel market, but they couldn't figure out how to get the government to pay for the r&d.

I don't know why the US never bought any Concordes for that route....