I think you're talking about the restriction on supersonic flight over land

No, that didn't help but I can see that in general it was probably necessary. As you say, Concorde was good for trans atlantic/pacfic routes and US airlines had orders in for (if I remember correctly) over a hundred planes.

The US government were a little upset about that (not invented here) and put their own SST project out to tender. It went to Boeing, who embarked on a comprehensive consultative stage with their customers and successfully got every last Concorde order cancelled. A few years later the SST project was killed by the government.

Rob