I don't know where exactly maize was cultivated, but Mexico comes from city Mexico-Tenochtitlan.

They found millenia old traces of maize in the valley of the Rio Balsa in Xihuatoxtla and also in the valley of Tehuacán.

Something about Coxcatlán phase. Couldn't find a name of a people who would have been responsible for the domestication.

It's easiest to say it happened in Mesoamerica.