For most of the 1840s, he devoted himself primarily to writing the history of Mexico from the perspective of a conservative. His three-volume work Disertaciones sobre la Historia de la Republica mexicana (Mexico, 1844–1849) and his five-volume Historia de México, desde los primeros movimientos que prepararon su independencia en el año de 1808, hasta la época presente (Mexico, 1849–1852), stand as the major intellectual productions of the Conservative Party in nineteenth-century Mexico, and the only histories produced by a Mexican author of his era to view the Spanish presence in his country favourably.
Among his more important actions are the creation of the Natural History Museum in Mexico City and the foundation of Mexico’s General National Archive. The latter has been very important for learning about the historical events in Mexico and understanding the political processes of the Mexican Republic. He also founded and ran a mining company, established the first metal foundry in independent Mexico in 1825, administered the estates of the descendants of Hernán Cortés, and served as president of the Mexico Cityayuntamiento (city council) in 1849.