Treated with contempt by their Spanish overlords, given to dissipation and grandiose proclamations, these fearless men nonetheless achieved military feats unsurpassed elsewhere in history. The aristocratic Simón Bolívar led his guerilla armies through swamp, jungle, and Andean ice to surprise his enemies and liberate most of northern South America. The inarticulate San Martín joined Bernardo O'Higgins, illegitimate son of a Spanish...