David Walker’s 1829 appeal for violent self-liberation was banned and followed by his death.

Evidence

We see it in David Walker, a free Black man who published his Appeal to the Coloured Citizens of the World in 1829, calling on enslaved people to rise up and liberate themselves, as white Americans had done, through violence if necessary. He wrote, “I speak Americans for your good. We must and shall be free I say, in spite of you. You may do your best to keep us in wretchedness and misery, to enrich you and your children, but God will deliver us from under you. And wo, wo, will be to you if we have to obtain our freedom by fighting.” These words demanding freedom proved so powerful that white Southerners banned the pamphlet; Walker was found dead a few months later. — Nikole Hannah-Jones et al., The 1619 Project, 1313