According to later accounts by Howe's daughter, Florence Hall, the Howes' South Boston home was a stop on the Underground Railroad. This is uncertain, but it is known that Howe vehemently opposed the Fugitive Slave Law. Two incidents clearly demonstrate this. The first occurred in May 1854, when Howe along with Thomas Wentworth Higginson, Theodore Parker and other abolitionists, stormed Faneuil Hall in order to try to free a captured escaped slave, Anthony Burns. Burns was going to be sent back to his slave owner in Virginia in accordance with the Fugitive Slave Law. The abolitionists hoped to rescue Burns from that fate. Howe declared outside the hall that "No man's freedom is safe until all men are free." Shortly afterward the abolitionists stormed the hall, breaking through the door with a battering ram. A deputy was accidentally shot in the ensuing fracas. Federal troops finally put an end to the attempted raid, and Burns was returned to Virginia. The men did not abandon Burns, however, and within a year of his capture, they had raised enough money to purchase Burns' freedom from his slave owner.