The leader of this self-defense movement was Santiago Vidaurri, who proclaimed the "Plan de Monterrey" in 1855, restoring the sovereignty of Nuevo León. Later a sympathizer with the Confederacy in the American Civil War, Vidaurri democratically annexed the Mexican state of Coahuila by plebiscite and later declared the República de la Sierra Madre, one of Nuevo León's two famous attempts at separatism (the other being the Republic of the Rio Grande in 1840). Upon the death of his chief military supporter, general Juan Zuazua, he was easily taken prisoner by other Nuevoleonese loyal to Benito Juárez, who decreed the deannexation of Coahuila.