This document discusses the history of Mexicans in the United States from prehistory to 1521. It describes Christopher Columbus' arrival in the Americas in 1492 and his mistreatment of native Americans. It also discusses the advanced pre-Columbian civilizations of Mesoamerica like the Aztecs and Mayans. Finally, it provides details about the Mexican revolutionary leader Emiliano Zapata who fought for land rights for peasants and was later assassinated.