For those of you who may not know:
It was one of the first alt-hist stories out there, and it was released by Robert Sobel in..............1973. That's right folks, 1973. Nixon was president, Lynyrd Skynyrd, America and other bands were on the airwaves, muscle cars were still making rounds, and the hippie movement was making way for blaxploitation movies and disco.
Anyway, the PoD was in 1777, and apparently the Revolutionaries lost the war, and several of what would have been America's founders are executed for high treason.............there are some Americans, however, who decide to leave. And guess where they end up? Mexico..............aka, 'New Spain'.
Starting in what is basically Texas{parts of N.M., Oklahoma, and Louisiana, too} in OTL, named 'Jefferson' in honor of the Founder, and then slowly working, one by one, eventually taking over all of Mexico, and renaming it............yep, you guessed it, the 'United States of Mexico', meanwhile, the Confederation of North America is born, as an appeasement to the people........basically.
I won't spoil anymore, though, so I'll just send you this link for a brief overview of the full timeline:
https://www.alternatehistory.com/gateway/analyses/FWOAN-timeline.html
http://www.kebe.com/for-all-nails/
So, what do you think...............?

{And for those of you who remember, you have any memories of this?}