In Kansas, the family was frequently persecuted by pro-slavery supporters. Cody's father spent time away from home for his safety. His enemies learned of a planned visit to his family and plotted to kill him on the way. Bill, despite his youth and being ill at the time, rode 30 miles (48 km) to warn his father. Isaac Cody went to Cleveland, Ohio, to organize a group of thirty families to bring back to Kansas, to add to the antislavery population. During his return trip, he caught a respiratory infection which, compounded by the lingering effects of his stabbing and complications from kidney disease, led to his death in April 1857.