 Mejía, son of José Antonio Mejía y María Gutiérrez, was born on July 28, 1792, in Rio Negro, in the province of Antioquia, in the Viceroyalty of New Granada in what is now Colombia.He studied in the "Colegio Mayor de San Bartolomé" between 1808 and 1812 in Santafé de Bogotá.Upon his return to Medellín, he taught philosophy in the "Colegio Provincial", in what is now the University of Antioquia.