“I always thought the Mach 3 XB-70 Valkyrie was impressive, even if it never did get into production.”
A neighbor of ours was one of the test pilots (Col. Joe Cotton).
For a while, in FL in the 60’s there were North American A5 (later A3J) Vigilantes, US Navy carrier-based. Land based (with nukes) at Sanford NAS of that time. Successor to the Douglas A3 Skywarrior.