2. Topic: Expansion and Sectionalism. Thesis: Colonial resistance to the "proclamation line" had been one of unifying factors that had committed many English colonists to revolution and helped spread an emerging nationalism. The exciting textbook American Nation, states that, "American independence and control of a wide and rich domain were the most obvious results of the Revolution." The revolution provided access to vast western lands and for many years western expansion would serve as an element that bound the various sections together. Yet as the decades rolled on and the United States added even more land in its march to the Pacific, expansionism led to sectionalism which resulted in the Union being torn apart.