The John Brown of the song "John Brown's Body" (1800-1859) was an American anti-slavery activist. He started out in Kansas, directing the murder of proslavery settlers during the conflict as to whether Kansas would be a slave or free state. Later he would attack the U.S. federal arsenal at Harpers Ferry, Virginia, and take people of the town hostage. Eventually the town was overrun by federal troops and Brown was captured, tried, convicted of "murder, treason, and inciting a slave insurrection" and hanged. Some abolitionists considered him a martyr to their cause, hence the song saying that his soul marches on as others worked to abolish slavery.