In the wake of mexico's disasterous loss to america in the mexican american war and the loss of land that happened in the Guadalupe Hidalgo, many people grew angry at the central government. Some of the regions had been indepedent in recent memory or at least attempted to become so. In the aftermath of the war they saw weakness and struck.
The Republic of the Rio grand was reborn and in the civil war that followed they succefully kicked the mexican government out of Sonora,Chihuahua,Coahuila,Nevevo Leon and the northern half of Tamailpas. The republic still stands to this day, in the south the Yucatan won their independence and grabed the whole of the pensular from Mexico.
Dispite their best efforts mexico never reconquered these territories, but what if mexico had regained these lands, what if mexico had managed to stay together what would the world look like today?