After the Mexican-American war, America claimed an expanse of land in the west. The question of whether this new land would be slave-states or free soil, was a hot topic and highly controversial and was in fact, the main cause of the Civil War. Even some of the other issues that may have led to the war can relate back to slavery. For instance: The south wanted to succeed from the union and have less control from the federal government, because they were trying to outlaw slavery not only in the southern states, but also keep the newly acquired land slave-free. Lincoln, in the beginning of his presidential campaign attempted to tone down slavery position and said the war was to “preserve the union” which was part of the cause of the war, however,