Anthony Burns was just twenty-eight years old when he died of tuberculosis in Ontario, Canada, on July 27, 1862. But thanks to his own fortitude and the efforts of legions of black and white antislavery activists, Burns died a free man. His story changed the course of American history, helping to turn northern public opinion against the cruelty of the federal Fugitive Slave Act. Confronted with the prospect that their silence in the face of Burns’s circumstances would be read as complicity with slaveholders, thousands of northerners instead took a stand against a policy that may have been legal but that would never be just.

Anthony Burns was born enslaved in Stafford County, Virginia, near the city of Fredericksburg, in 1834. From childhood, he wanted to be free, and early in 1854 he took the opportunity of being hired out in Richmond to stow away on a ship headed for Boston. There, he found work in a clothing store and kept quiet about his background. But when he wrote a letter to a brother who was still enslaved in Virginia, Burns inadvertently betrayed his location to his enslaver, a merchant named Charles Suttle, and Suttle wanted his “property” back. He armed himself with an order from a Virginia court that authorized him to seek Burns’s rendition from Massachusetts under the provisions of the Fugitive Slave Act of 1850, and then Suttle made his way to Boston, where he presented his case to a judge. The papers were in order, and on May 24, 1854, federal marshals approached Burns on the street and took him into custody. They detained him in the city’s federal courthouse pending a hearing before a federal commissioner authorized to determine cases involving purported fugitives.

Hearings under the provisions of the Fugitive Slave Act were notoriously stacked against those accused of being runaway slaves. This reality invigorated the efforts of interracial abolitionist organizations like the Boston Vigilance Committee, which had been helping fugitives from slavery avoid capture and find permanent freedom since the early 1840s. When word spread through the city that Anthony Burns had been arrested, committee members sprang into action. They arranged to have Richard Henry Dana, one of the most prominent lawyers in the United States, represent Burns at his hearing. Dana persuaded the federal commissioner, Judge Edward Loring, to postpone the hearing for several days so he might prepare a defense. In the interim, growing numbers of people in Boston reached the conclusion that no sham hearing was needed to demonstrate that Anthony Burns, like all enslaved people, deserved his freedom. They were motivated in part because just days earlier, under extraordinary pressure from slaveholders, the House of Representatives had passed the Kansas-Nebraska Act, which would allow slavery to spread to western territories and from there to take over the nation as new slave states swung the federal government behind slavery. With freedom seemingly on the defensive, many northerners determined that the answer to immoral laws was not procedural engagement with those laws. The answer was action.

On the night of May 26, thousands of protestors gathered at two different mass meetings to address Anthony Burns’s situation. A mostly white crowd met at Faneuil Hall under the auspices of the Boston Vigilance Committee. Wendell Phillips, Theodore Parker, and other leading abolitionists called for a forcible rescue of Burns, with Phillips urging the crowd to “see to it . . . that in the streets of Boston, you ratify the verdict of Faneuil Hall tonight, that Anthony Burns has no master but God!” At the nearby Tremont Temple, attendees at a meeting of black Bostonians did not need Phillips to rouse them. Several dozen of them marched to the courthouse to liberate Burns. Hundreds more streamed out of the meeting at Faneuil Hall, some armed with axes and other weapons.

Guards had locked and barricaded the courthouse, and several fired pistols over the throng from a third-story window. A newspaper reported that the gunfire only “seemed to exasperate the crowd most intensely, and a rush was made to the door.” When it held, the crowd located a wooden joist about ten feet long and used it as a battering ram, breaking down the courthouse door and touching off a brawl involving scores of federal marshals and city policemen. The rioters failed to rescue Burns, a deputy marshal was killed, and for the next several days the city was effectively placed under martial law, with militia units and a company of U.S. Marines stationed to guard the courthouse as “a crowd of persons, numbering at different times from two to ten thousand persons” assembled in the square outside the building.

On May 29, the hearing convened in the case of Anthony Burns, who sat manacled and surrounded by armed guards while Judge Loring, whose decision was final, determined his fate. Richard Henry Dana tried to persuade Loring that the provisions of the Fugitive Slave Law were unconstitutional, that Burns was not in fact Suttle’s slave, and that witnesses brought by Suttle were lying. Ultimately, he concluded with an appeal to Loring’s sense of right and wrong, reminding him that “the eyes of millions” were watching and imploring that his “judgment be for liberty and not for slavery.”

On June 2, 1854, Edward Loring ruled against Anthony Burns. Nearly everyone expected he would rule that way, since nearly every accused runaway subjected to the hearing system lost. But as a contingent of Marines led Burns out of the courthouse to the ship waiting to take him back to Virginia and back to slavery, fifty thousand people lined the streets leading to the wharf. They had hoisted American flags upside-down to signal distress, draped windows with the black bunting typically seen at funeral processions, and members of the crowd hissed, heckled, and jeered at the hundreds of militiamen, police officers, and federal troops deployed to keep order.

Back in Richmond, Burns spent months in a dank jail cell, an experience that ruined his health. Charles Suttle refused to entertain offers from abolitionists to purchase him and instead sold him to a man in North Carolina, where he would remain enslaved. It would take more than a year before Leonard Grimes, the black pastor of Boston’s Twelfth Street Baptist Church, could raise the money to secure Burns’s freedom in 1855 from the man to whom Suttle had sold him. Finally free, Burns attended Oberlin College and became a minister at black congregations in Indiana and in Canada, dying just months before Abraham Lincoln issued the Emancipation Proclamation that pointed toward slavery’s demise.

Anthony Burns made an impact in Boston and across the free states that long outlasted his trial. In its aftermath, abolitionists in Boston formed a secret organization called the Boston Anti-Man-Hunting League to resist the Fugitive Slave Act. In protest at an Independence Day event the summer after the Burns decision, William Lloyd Garrison, the nation’s most prominent abolitionist, publicly burned copies of the Fugitive Slave Act, Judge Loring’s decision, and the Constitution, declaring the last “a covenant with death and an agreement with hell.” After Anthony Burns, no fugitive would ever again be taken back into slavery from Massachusetts.

But the most significant impact made by Anthony Burns and his trial was not on white abolitionists who already opposed slavery or on black Americans who knew the horrors of that institution all too well. It was instead on those white northerners who, before Burns’s arrest, thought that because they lived in free states, they were not implicated in the evils of slavery.

Amos Lawrence, a Boston merchant whose family’s wealth derived from the textile industry and thus from cotton grown by slave labor, wrote to his uncle that the Burns affair had radicalized him and many of his fellows who had before considered themselves agnostic. “We went to bed one night old-fashioned, conservative, compromise Union Whigs,” Lawrence claimed, “and waked up stark mad Abolitionists.” Moving the political beliefs of white northerners was never really as simple as that, of course. Many would never be persuaded that the slave’s cause was the cause of universal human freedom. But for many others, Anthony Burns and the cases of other fugitives like him shamed a nation and scuttled its pretenses as a beacon of liberty to the world. The pretenses were still worth a fight.