This was the result of the courts that convened in Spain in 1810 amid the Napoleonic invasion and by March 1812, the Spanish political nation emerged (at least on paper), which was made up of the inhabitants of both continents, although already by April 1810, in Caracas, a process of rupture with the Spanish monarchy had begun and in September (Grito de Dolores) the same would happen in New Spain.

In any case, the Constitution of Cádiz was the doctrinal inspiration for all of America and Europe, and its political and legal elements prevailed in the legislative practice of nineteenth-century Mexico such as the division of powers, the residence of sovereignty in the nation, and the recognition of the rights of citizens.

When the Independence was consummated, Agustín de Iturbide chose and established the Sovereign Provisional Governing Board and appointed the members of the regency that would organize the elections of the deputies of the Constituent Congress.

This Congress did not issue any Constitution and had a tense relationship with Iturbide, who ordered the dissolution of the legislative body. The events after the Casa Mata Plan led to the restoration of Congress in early 1823, while Iturbide (Agustín I) abdicated the throne.
Congress created the Supreme Executive Power and declared the Empire as illegal.