At peak, the U.S. was covered by ~265 Nike ABM installations. The Nike installations were anti-aircraft, not anti-ballistic missile. https://en.wikipedia.org/w

At peak, the U.S. was covered by ~265 Nike ABM installations. The Nike installations were anti-aircraft, not anti-ballistic missile. https://en.wikipedia.org/wiki/Project_Nike https://en.wikipedia.org/wiki/Project_Nike The Safeguard Program was ABM. Since it was infeasible at the time to directly strike an incoming ICBM warhead, the interceptor rockets used nuclear warheads. That way they would only need detonate "close" to the incoming warhead. Only one Safeguard site was completed, and it was deactivated after the USA and the USSR signed an Anti-Ballistic Missile treaty. https://en.wikipedia.org/wiki/Safeguard_Program https://en.wikipedia.org/wiki/Safeguard_Program