Christopher Columbus's arrival in the New World had many negative effects. Columbus's discovery of the New World for Spain meant that hundreds of conquistadors would come and try to find wealth and a way to China. These explorers brought diseases and waged violence that would ultimately wipe out over ninety percent of the natives living in the New World. The Spanish also enslaved Native Americans, destroyed their religious symbols, and destroyed their culture.

Biologically, Columbus's discovery also had negative consequences on both sides of the ocean. In addition to the diseases brought to the New World, the Old World also gained many vegetables, such as squash and potatoes, through the Colombian Exchange. This enabled more people in Europe to live longer, more productive lives, which was positive. However, the increased population in Europe also made resources scarcer, and this would ultimately push more people to go to the New World in order to find riches. This population shift hurt the Native Americans, who saw their lands decrease with each passing year. European animals such as pigs also destroyed Native American crops.