The sight of federal marshals and slave catchers on the streets of Philadelphia, Boston, or even North Elba incensed abolitionist and even larger numbers of more moderate Northerners. A fugitive in chains being returned to slavery and the South personalized the issue and made it real for thousands of Northerners for whom, up to this point, slavery had been a hazy abstraction. For an already committed abolitionist like John Brown, the new law was an abomination.
In the wake of a well-publicized case of a runaway being returned to slavery in 1851, Brown composed a manifesto and presented it to a group of free black friends in Springfield. Massachusetts. Entitled “Words of Advice: Branch of the United States League of Gileadites..., Brown's essay urged African Americans to band together to resist the Fugitive Slave Law and all who sought to enforce it—even to the point of killing slavecatchers. “Be firm, detached, and cool,” Brown wrote, “stand by one another and by your friends, while a drop of blood remains; and be hanged, if you must, but tell no tales out of school. Make no confession.” Taking a page from the African American abolitionist Henry Highland Garnet (who preached slave rebellion), Brown attempted to foment an armed resistance against the Fugitive Slave Law. Inspired by what they heard, forty-four black men and women in Springfield joined Brown's United League of the Gileadites. Without Brown's presence, however, the group took little action.