The institution of slavery created problems for the United States from the very start. In the early republic, battles emerged over the westward expansion of slavery and over the role of the federal government in protecting the interests of slaveholders. Northern workers felt that slavery suppressed wages and stole land that could have been used by poor whites to secure their economic independence. White southerners feared that without slavery’s expansion, the abolitionist faction would come to dominate national politics and an increasingly dense population of enslaved people would lead to bloody insurrection and race war. Constant resistance from enslaved men and women required a strong proslavery government to maintain order. Enslaved men and women escaped to the North, and northerners and southerners disagreed sharply on the role of the federal government in capturing and returning these freedom seekers. While northerners appealed to their states’ rights to refuse to serve as slave catchers, southerners demanded federal protections for slavery. Enslaved laborers meanwhile remained vitally important to the nation’s economy, fueling not only the southern plantation economy but also providing raw materials for the industrializing North. Problems over slavery bedeviled American politics, especially as the United States expanded westward. After decades of conflict, Americans began to fear that freedom and slavery could no longer co-exist and that the country would become all one or the other. By 1860, the national political parties holding the regions together had splintered while the newly formed Republican Party opposing slavery’s expansion had gained northern constituents. During the secession crisis that followed in 1860 and 1861, fears, nearly a century in the making, at last devolved into bloody war.