After his ordination as a Catholic priest, Zugastegui was committed to serve the people in the confessional. On afternoons that he was free, he would go to a cafe which was popular with the unemployed men of the city who wished to discuss the current events of the day. On 11 August 1808 he was vocal and vehement in his support of Mexican independence from the Spanish Empire and in support of the call for a national convention to discuss the establishment of a local government due to the seizure of the Spanish Crown by Napoleon. This step was opposed by the Audiencia Real, the legislative authority of the colony. The Viceroy, José de Iturrigaray, on the other hand, was in favor of the congress and had the support of the Criollos (locally born children of Spanish colonists) segment of the population.
