Multiple choice How did John Brown contribute to the abolitionist movement? John Brown fought for the Union John Brown fought for the Confederacy He had anit-slavery raids in Kansas and at Harper's Ferry He worked on the underground railroad Reveal answer Fill a bubble to check yourself C Correct answer Explanation John Brown was a radical abolitionist who believed in armed insurrection to end slavery. His most famous actions were the Pottawatomie massacre in Kansas and the raid on the federal armory at Harpers Ferry.