Columbus sought gold on behalf of the Spanish monarchs, who financed his voyage in the hopes that he might discover great riches. We have to remember that Columbus was seeking a quicker water route to Asia, one that his sponsors hoped would give Spain control over trade with that region. As Zinn points out in the first chapter, finding gold would give Columbus great wealth and prestige, as he had been promised "10 percent of the profits, governorship over new-found lands, and the fame that would go with a new title: Admiral of the Open Seas." So by adding to the power of the monarchs of the newly-formed nation-state of Spain, Columbus could make himself a very rich man.
Zinn emphasizes these pecuniary motives above the religious zeal that many scholars also attribute to Columbus. His commitment to spreading Christianity dovetailed nicely with a quest for wealth and power. In the first chapter of A People's History, Zinn juxtaposes this craving for wealth with the "hospitality" and "belief in sharing" that characterized the Arawak people that inhabited the Bahamas, where Columbus first made landfall. Zinn shows how this clash of cultures proved deadly for the Native peoples, who lacked both resistance to disease Spaniards brought and the military technology that they possessed.