A historical anecdote I find quite interesting is Leopold of Hohenzollern-Sigmaringen being offered the Spanish throne in 1868.
This had brought up another idea that I figured you might find interesting.
Say the Confederate States of America survived, shattering the Monroe Doctrine and opening up Latin America to European meddling. This seems reasonable, as France tried to install an Emperor in Mexico and Spain briefly reintegrated Dominica into their empire.
At the time, Spain still had not recognized the independence of Peru, had their been no enforceable Monroe Doctrine, might Spain try to retake Peru during the Chincha Islands War? After all, France meddled in Mexico, and Spain reclaimed Dominica, so maybe they press their luck?
Now, assuming France losses the Franco-Prussia War, Napoleon III will be toppled, and Leopold of Hohenzollern-Sigmaringen might ascend to the Spanish throne . Mexico, ruled by a Hapsburg, may rely on it's other benefactor, Austria. So essentially Mexico is ruled by a Hapsburg, and Spain by a Hohenzollern, we might assume that Austria and Prussia quickly reconcile their differences (as IOTL) , and an German, Austrian, Spanish axis forms, which continues to meddle in the Latin World.
What do you think?