“Accounts of outrages committed by mobs form the every-day news of the times. They have pervaded the country from New England to Louisiana, they are neither peculiar to the eternal snows of the former nor the burning suns of the latter; they are not the creature of climate, neither are they confined to the slaveholding or the non-slaveholding States. Alike they spring up among the pleasure-hunting masters of Southern slaves, and the order-loving citizens of the land of steady habits. Whatever then their cause may be, it is common to the whole country. […] Such are the effects of mob law, and such are the scenes becoming more and more frequent in this land so lately famed for love of law and order, and the stories of which have even now grown too familiar to attract anything more than an idle remark. But you are perhaps ready to ask, "What has this to do with the perpetuation of our political institutions?" I answer, "It has much to do with it."”

"No Compromise with the Evil of Slavery" (1854) essay http://etc.usf.edu/lit2go/185/civil-rights-and-conflict-in-the-united-states-selected-speeches/5061/no-compromise-with-the-evil-of-slavery-speech-1854/

A Plea for Captain John Brown (1859)
Context: It was his peculiar doctrine that a man has a perfect right to interfere by force with the slaveholder, in order to rescue the slave. I agree with him. They who are continually shocked by slavery have some right to be shocked by the violent death of the slaveholder, but no others.

By no precedent, no example, no law, no compact, no purchase, no bequest, no inheritance, no combination of circumstances, is slaveholding right or justifiable. While a slave remains in his fetters, the land must have no rest.
“No Compromise with the Evil of Slavery” (1854) essay http://etc.usf.edu/lit2go/185/civil-rights-and-conflict-in-the-united-states-selected-speeches/5061/no-compromise-with-the-evil-of-slavery-speech-1854/

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 95.

Sermon 1
Context: The people of Israel, through the Mother of the Saviour, were kinsmen of Christ. But in the kingdom of God ties of blood are not sufficient... Christ, therefore, rejects the ties of blood; He demands the tie of faith, the hearing of the word of God. Whoever is united with Christ by baptism and by living faith is mother or brother to Him. So the question is not : Was Christ a Jew or an Aryan? It is : Are we members of Christ by baptism and by faith? For in Christ Jesus neither circumcision availeth anything, nor uncircumcision; but a new creature (Gal. vi, 15).

1860s, Should the Negro Enlist in the Union Army? (1863)

The History of Freedom in Antiquity (1877)
Context: Before God, there is neither Greek nor barbarian, neither rich nor poor; and the slave is as good as his master, for by birth all men are free; they are citizens of that universal commonwealth which embraces all the world, brethren of one family, and children of God.

1870s, The History of Freedom in Antiquity (1877)

James M. McPherson. The Illustrated Battle Cry of Freedom (2003)
2000s