San José de Mayo
Álvarez supported the Empire of Brazil over the Cisplatine Province (today's Uruguay) and worked at several government posts during the government of Carlos Federico Lecor. When the province seceded from Argentina and Brazil to become Uruguay, he was a member of the Constitutional Congress of the new country for San José de Mayo (1830). Since 1829 he was editor of the "El Constitucional" newspaper in Canelones.