Each of these ideas had many documents during that time to support their idea and one after the other, each document proved to be more vital in causing to a civil war. From the first document on Manifest Destiny on August 9, 1842 to the novel written to further the message of Uncle Tom's Cabin in 1957, the people drifted apart each step of the way. The war may officially not have begun till the year 1861, but it started in the minds of the people all the way back in 1942 - A difference of nineteen years!
Manifest Destiny played a major role in leading to a future Civil War. The country's legacy stating that we must extend from sea to shining sea cause extreme differentiations among the minds of the people. Not all the citizens wished for a large country; many were in fact satisfied with what they had. Many were afraid that more people meant more opposition that they did not wish to deal with. The Man in power, of course, gets to make the decision for all. In this case it was President James Knox Polk. He felt strongly believed in Manifest Destiny causing him to take control and put his plans into action. Though he was the culprit found when manifest destiny was at its peak, he was not the only man responsible. Many others, such as John Tyler and John L. O'Sullivan were supporters of Manifest Destiny.
The document initiating the idea of Manifest Destiny was the Webster-Ashburton Treaty (http://avalon.law.yale.edu/19th_century/br-1842.asp). Written as a series, this treaty settled disagreements amongst Great Britain and the United States of America about the boundaries in the northeast as well as the area near the great lakes. The great, endless dispute between the Maine- New Brunswick border and the Lake Superior- Lake of the Woods border had finally come to an end. The finally result- the United States of America was bestowed with the land in northern Maine as well as more land near the Great Lakes. The treaty not only marked an end to the dispute between the Americas and the British, but it ended an undeclared war-the Aroostook War. High tensions and heated rhetoric in Maine and New Brunswick motivated both sides to raise troops and attack against each other. The unofficial fighting had finally come to a halt. John Tyler's signing of the Webster-Ashburton Treaty slowly made evident that he greatly wished for territorial expansion of the nation. This territorial expansion may have been a small thing, but it was the beginning of what was to come next.