McClintock was an assistant professor of mathematics (1836–1837), professor of mathematics (1837–1840), and professor of Latin and Greek (1840–1848) at
Dickinson College,
Carlisle, Pennsylvania. He opposed the
Mexican–American War, as well as
slavery, but did not consider himself an abolitionist. In 1847, McClintock was arrested on the charge of instigating a riot, which resulted in the rescue of several fugitive slaves; his trial, in which he was acquitted, attracted wide attention. The trial dealt with the issue of
Personal liberty laws in the North and the fugitive slave crisis. When
Stephen Olin, president of Wesleyan died, the chair was offered to McClintock, but he preferred the call to the editorship of
The Methodist Quarterly Review, later renamed
The Methodist Review, a post he held for eight years, from 1848 to 1856. In 1855, he declined the presidency of
Troy University. From 1857 to 1860, McClintock was pastor of St. Paul's Methodist Episcopal Church in
New York City. From 1860 to 1864, he was in charge of the American chapel in Paris. There and in London, he did much to turn public opinion in favor of the Northern States. In 1865 to 1866, he was chairman of the central committee for the celebration of the centenary of American
Methodism. He retired from the regular ministry in 1865, but preached in
New Brunswick, New Jersey, until the spring of 1867, and in that year, at the wish of its founder,
Daniel Drew, became the first president of the newly established
Drew Theological Seminary at
Madison, New Jersey (later,
Drew University), where he died. At Drew, McClintock also served as professor of practical theology from 1867 until his death in 1870. A preacher, orator, teacher, and versatile scholar, McClintock by his editorial and educational work probably did more than any other man to raise the intellectual tone of American Methodism, and, particularly, of the American Methodist clergy. ==Works==