Princeton University, in the words of colonial historian Jeff Looney, cannot be said to have had a "glowing history in opposing slavery." He and fellow historian John Murrin both state that John Witherspoon, president of the College of New Jersey from 1768-1794, owned slaves. Indeed, Varnum Lansing Collins notes that the inventory of Witherspoon's possessions taken at his death included "two slaves . . . valued at a hundred dollars each." Neither Murrin or Looney have any reason to believe that the College itself owned slaves, though individual trustees did.
Israel Read, for example, who served as a trustee from 1761 to 1793 and was the first Princeton graduate to become a member of the synod of the Presbyterian church, disposed of three slaves upon his death, two to his children and one to a life of freedom (see Princetonians: 1748-1768). Jeremiah Halsey of the Class of 1752, a trustee from 1770 to 1780 and Clerk of the Board beginning in 1772, as well as the College's longest serving 18th-century tutor, also owned a slave (see Princetonians: 1748-1768). Richard Stockton of the Class of 1779, a trustee from 1791 to 1828 and the first citizen of Princeton, reputedly owned several slaves, freeing one in 1823 (Princetonians: 1776-1783). On the other hand, Joseph Bloomfield, a trustee from 1793 to 1801 and 1819 to 1823, was a prominent abolitionist, serving as president of the New Jersey Society for the Abolition of Slavery. As Governor of New Jersey from 1801 to 1812, Bloomfield presided over legislation enacted in 1804 that provided for the gradual abolition (over a twenty-year period) of slavery in the state.
Looney noted that the College offered a congenial home for Southerners since it numbered many "colonizationists" among its faculty, including John Maclean, president of the College of New Jersey from 1854 to 1868, who was a member of the American Colonization Society, which sought to repatriate blacks to Africa. Princeton attracted more Southerners than Harvard and Yale, and during the 1840s, there was only one year in which the percentage of Southern students at Princeton fell below 40%, and in 1848, it stood at 51.5% (see "Answering 'The Trumpet to Discord': Southerners at the College of New Jersey, 1820-1860, and Their Careers," a senior thesis by Ronald D. Kerridge). Gradualism was the order of the day at Princeton in the first half of the 19th-century, and the same could be said of New Jersey as a whole. As Kerridge puts it, "New Jersey was very conservative on the slavery question as free states went, and Mercer County and the town of Princeton were no exceptions. David A. Hillstrom's thorough study of the colonization and abolition movements in New Jersey (also a senior thesis) reveals strong support for the former but little backing for the more aggressive anti-slavery position." (source: Princeton University)