Consists of selected papers of the Maclean family, particularly John Maclean (1771-1814), the first professor of chemistry at Princeton University, then called the College of New Jersey. John Maclean was born in Scotland and educated to become a surgeon like his father. He came to the United States in 1795 and, on the advice of Benjamin Rush, established himself in Princeton in the practice of "physic" and surgery. In October 1795, Maclean was appointed professor of chemistry at Princeton. In 1798, he married Phebe Bainbridge, the eldest daughter of Absolom Bainbridge and Mary Taylor Bainbridge of Middletown, New Jersey. Phebe's brother was United States Navy Commodore William Bainbridge (1774-1833). John and Phebe Maclean's eldest son, John Maclean Jr. (1800-1886), became Princeton's tenth president in 1854.

Materials in this collection include ten letters written by John Maclean (1777-1814), including letters addressed to Benjamin Silliman (1779-1864), the first lecturer at Yale in chemistry for whom Maclean served as mentor in the teaching of chemistry; Samuel Stanhope Smith (1751-1819) and Ashbel Green (1762-1848), the seventh and eighth presidents of Princeton; Major Benjamin Walker (1753-1818), United States Representative from New York; and Joshua Maddox Wallace. The letter to Ashbel Green concerns the student rebellion and suspensions in 1807. There is also a manuscript containing biographical details of Maclean's life, an extract of a letter of introduction by Dr. Miller of Glasgow to Dr. Caspar Wistar (1761-1818) of Philadelphia on Maclean's behalf, and Maclean's medical license from the State of New Jersey.

Materials related to John Maclean Jr. (1800-1886) include his Princeton Theological Seminary diploma and an honorary doctorate from the University of the State of New York. There is also some legal correspondence of Archibald Maclean (1810-1894), family letters from William Bainbridge, and a power of attorney document for Mary B. Maclean. Of note is a bound volume containing a detailed genealogy of the Maclean, Bainbridge, and Taylor families.

This collection was formerly referred to as the "John Maclean Collection" and the "John Maclean Letters and Papers."