McPherson points out that even if Confederates genuinely fought over states' rights, it boiled down to states' right to slavery. McPherson writes concerning states' rights and other non-slavery explanations: States' rights was an ideology formulated and applied as a means of advancing slave state interests through federal authority. As historian Thomas L. Krannawitter points out, the "Southern demand for federal slave protection represented a demand for an unprecedented expansion of Federal power." Before the Civil War, the Southern states supported the use of federal powers to enforce and extend slavery, as with the Fugitive Slave Act of 1850 and the Dred Scott v. Sandford decision. The faction that pushed for secession often infringed on states' rights. Because of the overrepresentation of pro-slavery factions in the federal government, many Northerners, even non-abolitionists, feared the Slave Power conspiracy. Some Northern states resisted the enforcement of the Fugitive Slave Act. Historian Eric Foner states that the act "could hardly have been designed to arouse greater opposition in the North. It overrode numerous state and local laws and legal procedures and 'commanded' individual citizens to assist, when called upon, in capturing runaways." He continues, "It certainly did not reveal, on the part of slaveholders, sensitivity to states' rights." According to historian Paul Finkelman, "the southern states mostly complained that the northern states were asserting their states' rights and that the national government was not powerful enough to counter these northern claims." The Confederate Constitution also "federally" required slavery to be legal in all Confederate states and claimed territories. Sectionalism Sectionalism resulted from the different economies, social structure, customs, and political values of the North and South. Regional tensions came to a head during the War of 1812, resulting in the Hartford Convention, which manifested Northern dissatisfaction with a foreign trade embargo that affected the industrial North disproportionately, the Three-Fifths Compromise, dilution of Northern power by new states, and a succession of Southern presidents. Sectionalism increased steadily between 1800 and 1860 as the North, which phased slavery out of existence, industrialized, urbanized, and built prosperous farms, while the deep South concentrated on plantation agriculture based on slave labor, together with subsistence agriculture for poor whites. In the 1840s and 1850s, the issue of accepting slavery (in the guise of rejecting slave-owning bishops and missionaries) split the nation's largest religious denominations (the Methodist, Baptist, and Presbyterian churches) into separate Northern and Southern denominations. Historians have debated