American slavery ended in the awful carnage of the Civil War. But to conclude Abolitionism was a failure that made no contribution to abolition of slavery (or to the cause of civil liberty) would be a grave mistake. Abolitionists divided between those who rejected political action and those who embraced it, between those who thought the Constitution was an agreement with Hell and those who read it as outlawing slavery, at least in all the federal territories.
The political abolitionists embraced the Declaration of Independence's claim that "all men are created equal." They read the 5th Amendment's guarantee that no person shall be deprived of life, liberty or property without due process of law to mean that slavery in federal territories was unconstitutional. As the Liberty Party Platform of 1844 put it, "all attempts to hold men as property within the limits of exclusive national jurisdiction ought to be prohibited by law." The Liberty Party got only a tiny vote in 1844, but in 1848, the political abolitionists joined others in the Free Soil Party. Its platform had very similar language, and the Free Soil Party got a substantial popular vote. The Republican Party platforms of 1856 and 1860 contained very similar language.
Many political abolitionists joined the Liberty and Free Soil coalitions and the Republican coalition that elected Lincoln. These parties favored a policy of federal containment and roll back of slavery in federal territory, not immediate federal abolition in the original slave states. Still, they saw slavery in the slave states as an evil that should be eliminated. In 1860, about half of the Republicans in the House of Representatives had endorsed Hinton Helper's book. The Impending Crisis, advocating state by state abolition of slavery in the South. Circulation of the book in slave states was a crime.
Containment did not mean the Liberty, Free Soil, and Republican parties were not in favor of abolition of slavery, any more than containment of Communism in the 1950s meant that the United States was not anti-Communist.
The great contribution of the abolitionists, political and anti-political, (and the Southerners who demanded opening all federal territory to slavery and who demanded that Northern states silence abolitionists) was to put the issue of slavery and civil liberty squarely on the political agenda. At first Northern mobs broke up abolitionist meetings and attacked abolitionist newspapers in an effort to suppress anti-slavery speech. In Alton, Illinois abolitionist Elijah Lovejoy was killed defending his newspaper press from a mob.
Abolitionists and more and more Americans reframed the slavery issue as one of civil liberty, free speech and free press. Many non-abolitionists in the North rallied to support free speech rights of abolitionists. As these people saw it, slavery threatened the liberty of Northerners as well. In the South, meanwhile, in 1856 and 1860, laws and mobs made campaigning by Republicans impossible.
In 1856, the Republican Party advocated free speech, free press, free territories, free men, and Fremont. In 1860, a Republican resolution in the United States Senate said freedom of speech and press on slavery and "every other subject of domestic and national policy should be maintained inviolate in all the States." Thanks in part of the efforts and sufferings of abolitionists, slavery and its relation to civil liberty were squarely on the political agenda.
In 1862 Republicans in Congress outlawed slavery in the District of Columbia and in all federal territories---realizing the promises of the Liberty Party, Free Soil, and Republican Party platforms. In 1864 and 1865 debates on abolition of slavery, Republicans recounted attacks on free speech of abolitionists.
The Fourteenth Amendment's guarantees of privileges and immunities of citizens of the United States and equal protection and due process for all persons--and its attempt to require states also to respect the liberties in the federal Bill of Rights--where part of the legacy of the political abolitionists. Of course, the legacy of slavery was not fully extinguished in 1865. Still, Abolitionists made a major contribution to the struggle for liberty.
Michael Kent Curtis teaches at Wake Forest University School of Law. He is the author of "Free Speech: The People's Darling Privilege: Struggles for Freedom of Expression in American History," among others.
Note: Here's a recent article with a somewhat different perspective.