 As a liberal politician, Altamirano opposed Benito Juárez's continuation in office in 1861, allying himself with other liberal foes of Juárez and supporting Jesús González Ortega.With the French invasion of Mexico in 1862, Altamirano understood how dire the situation was for Mexico, since unlike the U.S. invasion (1846–48), which united Mexicans against the invader, the French were supported by Mexican conservatives.His best-known novel is "El Zarco", which is set in Yautepec, Morelos during the Reform War of 1857–1860.