In November 1834, at Rankin's Ripley church, Weld began a year-long series of speeches throughout Ohio that raised the profile of the abolitionist movement in the state; at his urging Rankin did likewise. Many local anti-slavery socities were founded.  in April of 1835 an Ohio Anti-slavery Society was formed, at whose initial meeting in Putnam, Ohio (today Zanesville), both Rankin and Weld played key roles. On his way home, Rankin had his first real experience with mob opposition to his efforts, as he was showered with rotten eggs. When he stopped in Chillicothe to speak at a church, stones were thrown through a window. In 1836, Weld invited Rankin to join a group called "the Seventy", who were selected by the American Anti-Slavery Society to travel to churches throughout the Northern states preaching immediate emancipation ("immediatism") and forming local anti-slavery societies. Released by his congregation for one year to participate in the effort, Rankin's passion for the cause grew with the opposition to his "dangerous" views, even among many who opposed slavery but feared provoking a slave uprising. A bounty of up to $3,000 was placed on his life, and in 1841 he and his sons had to fight off attackers who came to burn his house and barn in the middle of the night. Ulysses S. Grant was a student at Rankin's Presbyterian Academy in Ripley in the fall of 1838. Grant entered the U. S. Military Academy in 1839. The passage of the Fugitive Slave Law of 1850 heightened the danger and profile of their assistance to runaways as it was now illegal to do so, even in free states. At an anti-slavery society meeting in Highland County, Ohio, held by Rankin and Salmon P. Chase, however, Rankin declared that "Disobedience to the enactment is obedience to God." Opposition within his own congregation, spurred by Rankin's attempts to expel slaveowners from the church, finally led him to resign in 1846 after 24 years as minister of the Ripley Presbyterian Church. Over one-third of the church's members left with him and helped Rankin establish what eventually came to be the Free Presbyterian Church, which may have had as many as 72 congregations before the coming of the Civil War. After the war, Rankin welcomed the reunion of the Presbyterian churches in Ripley. In May 1892, six years after John Rankin's death, a monument aptly named "Freedom's Heroes", was dedicated to Rankin and his wife, Jean Lowry Rankin, on the grounds of the Maplewood Cemetery in Ripley, Ohio.