Mainly it’s because not a single human being in Mesoamérica spoke any form of Spanish before, uh, the Spaniards turned-up. (And began committing their genocide)
The question was asking why Castilian was taught, as opposed to any other dialect/form of Spanish that is spoken in geographically proximous states to the US.
You may want to reread the question as your answer makes zero sense.
which part don’t you understand? maybe I can explain
Mainly it’s because not a single human being in Mesoamérica spoke any form of Spanish before, uh, the Spaniards turned-up. (And began committing their genocide)
The question was asking why Castilian was taught, as opposed to any other dialect/form of Spanish that is spoken in geographically proximous states to the US.