From a 4th of July speech to the citizens of Rochester, NY in 1852:
"...At a time like this, scorching irony, not convincing argument, is needed. O! had I the ability, and could reach the nation's ear, I would, to-day, pour out a fiery stream of biting ridicule, blasting reproach, withering sarcasm, and stern rebuke. For it is not light that is needed, but fire; it is not the gentle shower, but thunder. We need the storm, the whirlwind, and the earthquake. The feeling of the nation must be quickened; the conscience of the nation must be roused; the propriety of the nation must be startled; the hypocrisy of the nation must be exposed; and its crimes against God and man must be proclaimed and denounced.
What, to the American slave, is your 4th of July? I answer; a day that reveals to him, more than all other days in the year, the gross injustice and cruelty to which he is the constant victim. To him, your celebration is a sham; your boasted liberty, an unholy license; your national greatness, swelling vanity; your sounds of rejoicing are empty and heartless; your denunciation of tyrants, brass fronted impudence; your shouts of liberty and equality, hollow mockery; your prayers and hymns, your sermons and thanksgivings, with all your religious parade and solemnity, are, to Him, mere bombast, fraud, deception, impiety, and hypocrisy -- a thin veil to cover up crimes which would disgrace a nation of savages.There is not a nation on the earth guilty of practices more shocking and bloody than are the people of the United States, at this very hour.
...Allow me to say, in conclusion, notwithstanding the dark picture I have this day presented, of the state of the nation, I do not despair of this country. There are forces in operation which must inevitably work the downfall of slavery. "The arm of the Lord is not shortened," and the doom of slavery is certain. I, therefore, leave off where I began, with hope. While drawing encouragement from "the Declaration of Independence," the great principles it contains, and the genius of American Institutions, my spirit is also cheered by the obvious tendencies of the age. Nations do not now stand in the same relation to each other that they did ages ago. No nation can now shut itself up from the surrounding world and trot round in the same old path of its fathers without interference. The time was when such could be done. Long established customs of hurtful character could formerly fence themselves in, and do their evil work with social impunity. Knowledge was then confined and enjoyed by the privileged few, and the multitude walked on in mental darkness. But a change has now come over the affairs of mankind. ..."
Born into slavery in 1817, Frederick Douglass escaped to the north in 1838 and became a leading orator in the Abolition movement and publisher of "The North Star" anti-slavery newspaper.