The documents below will help you determine the effects of the European diseases on the inhabitants of Meso-America during the first century after Columbus "sailed the ocean blue" in 1492. The first three documents address the pre-contact health of the peoples inhabiting the Western Hemisphere. Additional documents recount virgin soil epidemics from the perspectives of the Spaniards and the native peoples inflicted by diseases unfamiliar to them. Historians researching the health and illnesses of the past often rely on what is known today about particular diseases. One document below details current knowledge about smallpox; medical knowledge of how the disease affects the body can help historians evaluate the descriptions provided by those who lived through the epidemics of the sixteenth century.