Nassau Hall (or Old Nassau) is the oldest building at Princeton University in Princeton, Mercer County, New Jersey, United States. At the time it was built in 1756, Nassau Hall was the largest building in colonial New Jersey and the largest academic building in all the American colonies. The University, then known as the College of New Jersey, held classes for one year in Elizabeth and nine years in Newark before the Hall was completed in 1756. Designed originally by Robert Smith, the building was subsequently remodeled by notable American architects Benjamin Latrobe and John Notman. In the early years of Princeton University, Nassau Hall accommodated classrooms, a library, a chapel, and residential space for students and faculty. It housed the university's first Department of Psychology,