Thanks! I only knew the oft parroted version of the story from family members who worked at Boeing. I guess the detail I didn’t immediately recall was “plane over budget” (which likely lead to the government funding you mentioned being pulled). I still believe that the biggest reason for the ban was NIMBYs though, if you’ve ever been around sonic booms you know how intrusive they are. I lived just far enough away from a military base as a kid that we happened to be near where pilots would occasionally go super sonic as part of their training. After living in California years later and experiencing multiple earthquakes, I’d say the sonic boom was about like a magnitude 6, but only lasting for a couple seconds.