"The True History of the Conquest of Mexico" Bernal Diaz Del Castillo,  1927 (1st American Edition) 
This remarkable narrative offers firsthand insights from a soldier who served under Hernán Cortés, capturing the complexity and drama of the conquest of Mexico, including the brutal atrocities committed by the Spanish. Bernal Díaz del Castillo details the merciless tactics, harrowing massacres, and ruthless destruction brought upon the indigenous population, painting a vivid picture of the human cost of conquest. His account is celebrated for its vivid detail and unmatched authenticity.