On February 22, 1856, Abraham Lincoln was the featured speaker at a convention of newspaper editors meeting in Decatur, Illinois, the immediate precursor to the first formal gathering of the Illinois Republican Party. The convention had endorsed a set of resolutions that were copied almost verbatim from the resolutions of an earlier Anti-Nebraska convention held in Quincy. The delegates resolved to abide by all the constitutional rights the slave states were entitled to and affirmed the federal consensus, disclaiming any “purpose to annoy or disturb our sister States in the peaceful enjoyment of any of their rights.” But the editors also insisted that the right of property in slaves existed only “within the jurisdiction” of the slave states themselves. They called for the “restriction of Slavery to its present authorized limits” and implied that no new slave states should be admitted to the Union. Territories have no “constitutional right to demand admittance into the sisterhood of States” whereas Congress had a “duty” to prevent “any poisonous matter” from entering “into our extremities.” In addition to specific policies, the delegates endorsed the basic principle of anti-slavery constitutionalism:
We hold that our general government is imbued throughout the whole organization with the spirit of Liberty, as set forth originally in the Declaration of Independence . . . ; that it recognized FREEDOM as the rule and SLAVERY as the exception . . . , and that it nowhere sanctions the idea of property in man as one of its principles.
That evening, the convention’s work done, Lincoln spoke for half an hour “in his usual masterly manner, frequently interrupted by the cheers of his hearers.”
Most of what Lincoln had to say about slavery and the Constitution was packed into the six years between the Peoria address in late 1854 and his first inaugural address in early 1861. But in those years Lincoln proved an eloquent, if unoriginal, advocate for the antislavery constitutional tradition. He repeatedly insisted that the Constitution recognized slaves only as persons, never as property. He vowed to abide by the federal consensus by not interfering directly with slavery in the states where it existed, but he denounced the tendency to spread proslavery constitutional principles into the free states. He always said that the guiding spirit of the Constitution was the principle of fundamental human equality proclaimed in the Declaration of Independence. The antislavery Constitution shaped his antislavery politics. Lincoln believed that Congress could, “under the Constitution,” abolish slavery in Washington, DC, that the federal government could ban slavery from all US territories, and that accused fugitive slaves were entitled to the “privileges and immunities” of citizenship, in particular the rights of due process.