I understand, from my history lessons, that it was Del Riego's mutiny that prevented the metropolis from being able to organize a proper counter against the independentist movements in America:
http://en.wikipedia.org/wiki/Rafael_del_Riego
If either of these happened:
-Fernando VII accepting the liberal constitution of 1812
-Del Riego not being given command of one of the batallions that were to be sent to America
then Spain might have been able to resist effectively the American independence. They could have held onto the colonies longer. Maybe not all of them.
How long, how many? no idea.
The development would be radically different depending on the PoD: one of them stablishes Spain as a single entity, with no differences between the peninsular and the American Spaniards, under a liberal constitution, very different from OTL. The other one would be an extension of Spain's complicated XIX century to America. Carlists in America?
