So I've been reading some threads about the civil war and usually to have a succesful CSA, the british have to help them out, but today I had this idea what if instead there had been a CSA-Mexico alliance, the CSA could promise them the land they lost in the mexican-american war in exchange for their help, do you guys think the Union could still win? I personally think so even though it would be much bloodier and the US probably would end up annexing the northern states or maybe like others have said to the tropic of cancer, as punishment for helping the CSA
edit: of course assuming there was no french intervention in Mexico