Cantabene,
You're absolutely right. Eisenhower visited Spain in December of 1959, on a good will tour that was 19 days long, and included 11 countries.
I'd forgotten about that tour... sorry!
ex-Prez Jimmy Carter was there in September/October of 1998. He was there for dialogue with the Spanish government and ETA, in attempt to advance the fragile cease fire that existed. At that time, my wife and I had the opportunity of touring the Guggenheim museum with him and his family.
Wolf (Who's human too... don't shoot an endangered species!
)