In making their case that the Constitution favored freedom over slavery, the antislavery Northerners interpreted and parsed every part of it as imaginatively as possible, seeking to whittle away at the pro-slavery arguments while at the same time emphasizing every provision and every clause that could be used on behalf of freedom. Congress, they said, had the sole constitutional authority to prohibit slavery in the territories and, indeed, had an obligation to do so. It could also suppress the coastwise slave trade and abolish slavery in the District of Columbia. They claimed that many parts of the Constitution worked against slavery. The Fifth Amendment, for example, declared that no person could be deprived of liberty without due process of law, which the Northern opponents of slavery could use to stymie enforcement of the Fugitive Slave Acts. They stressed that the preamble of the Constitution granted the federal government the power to “secure the blessings of liberty” and that the Fourth Amendment guaranteed the right of people to be secure from unreasonable seizures. The antislavery Northerners argued that the privileges and immunities of citizens in Article IV, Section 2, were derived from the federal Constitution, not from the constitutions of the states, and thus Black citizens of the Northern states were entitled constitutionally to move freely from one state to another. They even invoked Congress’s war powers and the federal guarantee of a republican form of government to every state in Article IV, Section 4, to threaten slavery in the states. If the slave states ever seceded, the antislavery Northerners warned, they would forfeit their constitutional rights, and the free states would no longer be obliged to enforce the fugitive slave clause.
Gradually the antislavery advocates accumulated a variety of textual protections for freedom and limitations on slavery. Then they began moving beyond the text of the Constitution to invoke its spirit, which, they said, was mainly derived from the Declaration of Independence and its inspiring dedication to equality. By the 1850s the antislavery Northerners had built a powerful case for antislavery constitutionalism. They had created a “Constitution that made freedom the rule and slavery the exception.”
The Republican Party became the political embodiment of this antislavery constitutionalism, with Abraham Lincoln its most eloquent spokesman. So fearful were the Southern slaveholders of Lincoln and the Republicans that simply his election as president in November 1860 precipitated the immediate secession of many slave states. By Feb. 1, 1861, even before Lincoln took office in March, seven states had formed the Confederacy. Four more joined between April and June 1861.
Lincoln hated slavery as much as any abolitionist, but as an ambitious and sensitive politician in a radically democratic society he couldn’t ignore the feelings of the diverse constituents of Northern society. He believed in law and order and in the Constitution; and thus because of the Constitution’s ambiguity, he had to make his way along a very “crooked path” to achieve the ultimate extinction of slavery that he wanted. Despite all the backtracking and roundabout routes that Lincoln and his party followed, however, they never abandoned the central tenets of the antislavery constitutionalism that had developed over the previous half-century.
Through all his twists and turns Lincoln held firm to his belief that the guiding spirit of the Constitution was the principle of fundamental human equality proclaimed in the Declaration of Independence. Consequently, Oakes writes, “it became harder for Lincoln to distinguish his opposition to slavery from his baseline commitment to fundamental equality for whites and Blacks.” Because he came to realize that racial discrimination was really a means of supporting slavery, he moved toward a position of true racial equality. In the end, Oakes observes, “Lincoln became the first president to publicly endorse voting rights for Black men.”