Political map of North America & the Caribbean 18 October 1859 (Raid on Harpers Ferry): The 1850s conflict in the US over slavery (Abolitionism in the United States) was not limited to Kansas (Bleeding Kansas). In 1859, the abolitionist John Brown (John Brown (abolitionist)) and his followers attempted to start a slave revolt in Virginia by seizing the arsenal at Harpers Ferry (John Brown's raid on Harpers Ferry). Although he was defeated, Brown's raid and his subsequent execution further polarized the nation.