While I have read comparatively little about Stephen S. Foster (1809-81), I'd like to know more. Everything I have seen thus far makes me want to stand up and cheer.

Foster appears to have been solidly in the radical libertarian wing of abolitionism both on slavery and war. A strong proponent of natural rights, Foster advocated resistance to the Fugitive Slave Law, individual rights for women, rights in land to the ex-slaves who he regarded as the true owners, and, like his fellow New Englander, Lysander Spooner, opposed the Civil War.

In Revolution the Only Remedy for Slavery (1855) he endorsed both slave rebellions and a general anti-slavery revolution against the federal government. The entire tract is online (see link above) but here is a sampling:

In the Federal Union lies the grand secret of the strength of the slave power. Of itself that power is contemptibly weak. If in the countenances of their masters only the slaves discovered the visage of a foe, not another sun would go down upon an unbroken fetter. Backed by the entire body of non-slave-claimants of the south, it could have no strength to stand against the combined forces of the slaves, and their many sympathizers in the north, and in Europe. But in its alliance with the free States, through the Federal government, its strength is immense. It rules with a rod of iron, and none can say to it, “Why do ye so?” It kills, and it makes alive....It is able not only to command the services of the entire body of our militia when an insurrection is to be suppressed, an invasion to be repelled, or a slave to be recaptured, but it has seduced into its willing service, or awed into submission, nearly every prominent man throughout the entire north....

To the enlightened vision there is for this evil but one remedy. Our strength all lies in a single force—the conscience of the nation. All else is on the side of the oppressor. But conscience, that force of forces when properly instructed, is all, and always, on our side. It is to this element of strength, then, that our attention should be mainly directed. Our only hope is in being able to bring the conscience of the nation into active conflict with its present position, in respect to slavery, and thereby induce a radical change. What that position is we have already seen. The Constitution requires of the general government the protection of slavery in such of the States as choose to retain it, with no power to regulate or abolish it. Hence the private citizen has no course left to him but either to aid in upholding the system, or renounce his allegiance to the government. By this subtle device of the slave power the whole country has been leagued in defence of the institution, and the north reduced to a mere subjugated province of the plantation. The heart of the church has been corrupted by it, the conscience of the country fettered, and our statesmen converted into syncophants fawning at the feet of the slave power. Here, then, is the seat of this terrible disease, and here especially must the remedy be applied. Our first great work is to cut this Gordian knot,—the Union,—and set free the northern conscience from the restraints of the constitutional oath. Till this is done, all other efforts will prove of little avail. There is no hope for the slave, nor for the country, but in revolution.