The Fugitive Slave Act of 1850 made it a federal crime to aid an escaped slave or obstruct a rendition, and Northern juries were soon asked to imprison their neighbors for acts of open conscience. In Boston, crowds led by Black abolitionists freed Shadrach Minkins from a federal courtroom in February 1851; in Syracuse that October, a biracial crowd broke William "Jerry" Henry out of custody in the celebrated Jerry Rescue. Federal prosecutors indicted the rescuers in both cities and secured almost nothing — juries acquitted or hung, and only one Syracuse defendant, Enoch Reed, a Black laborer, was convicted, dying while his appeal was pending.
The climactic case came from Ohio: after the 1858 Oberlin–Wellington Rescue, thirty-seven men were indicted, and rescuers Simeon Bushnell and Charles Langston chose jail over recognizing the law's legitimacy. Langston's speech at sentencing became an abolitionist classic, and the spectacle of respected citizens imprisoned as political offenders did as much as any pamphlet to convince the North that the Slave Power had captured the federal courts.