Charles D. Cashdollar, "McClintock, John," American National Biography Online, February 2000, http://www.anb.org/articles/08/08-01967.html.
McClintock vigorously opposed slavery. In 1841 he wrote, "It seems to me that the Church can do only one thing in regard to so heinous a crime as slavery, namely, to bear her testimony against it, and use all her influence for its extirpation." He decried the annexation of Texas, and during 1847 he penned antislavery articles for the Christian Advocate, a prominent Methodist weekly. In June 1847 the arrival in Carlisle of two Maryland slaveowners pursuing fugitives raised local tempers. McClintock was not a participant in the violence that left one slaveowner badly beaten, but he was arrested and charged with having incited the attack; a jury acquitted him in August 1847. His own evaluation was that "my human and Christian sympathies were openly exhibited on the side of the poor blacks, and this gave mortal offence to the slaveholders and their confreres in the town."