How was Mexico federated?

Right after Mexico won its independence war against Spain (1810-1821), it became a monarchy, formally known as the First Mexican Empire (1821-1823). After a few years of a mismanaged economy, several Mexican generals with republican ideals staged a coup d'etat, switching to a federal republic and having Guadalupe Victoria (term: 1824-1829) as the first Mexican president.

Nowadays, Mexico is a federal presidential representative republic.