O'Sullivan was not alone in his belief that the whites were superior over other races. Before the abolishment of slavery in 1865, many whites wanted to expand it over the entire American continent. This is a testament to the fact that they believed in their superiority and felt that they could expand across the country and possess the land and the people who were already inhabitants. Since the northern states rejected the notion of slavery, it made sense for those clinging to the doctrine of manifest destiny to extend slavery westward. The southerners who believed in slavery felt that the warm climates of the western states and Mexico would be the perfect reason to expand slavery to this area (Dunning 113).
The persistent push towards the west and the need for continuous expansion gradually increased the conflict between the early inhabitants of the land and the colonists, leading to aggression. Upon their arrival in Massachusetts Bay, after their first encounter with the Native Americans, the colonists were quick to resort to violence, as an attempt to please their God. After confronting the natives, many believed that "…it pleased God to vanquish their enemies and give them deliverance…" (Bradford 85), indicating the fact that God was used to justify every action taken on behalf of the American population. Conflict with the Native Americans continued with the rise of Native American Removal Act, which drove the Natives who remained in the East to move to reservations. Of the many incidents that occurred during the process of enforcing the removal act, the most well-known is the "Trail of Tears," when President Martin Van Buren (President Jackson's successor) ordered the removal of about twenty thousand Cherokee that remained in the East as a sign of rebellion against the government.
The U.S. troops rounded off the Cherokee, who were then sent off in groups of about a thousand each, on an eight hundred mile journey in which many died along on the path that is now commonly referred to as the Trail of Tears, the route in which the Native Americans followed from Georgia to the Indian Territory (Danzer 130). As reflected in the apathy portrayed towards the Cherokee, under the leadership of the American government, the United States Army did not tolerate any resistance to the removal, and with the clearing of the Native Americans, Americans concentrated on the development of transportation which was used to facilitate the volume of trade and manufacturing, as well as infrastructure. As the prospects of statehood over the majority of the western territories became more transparent, the nation tackled the issue of slavery in the West, contributing to the causes of the Civil War, which inhibited the rate of expansion. Nonetheless, expansion accelerated over the last several decades of the nineteenth century, after the completion of the rural and urban infrastructure, as well as the transcontinental railroad, and, the complete removal