The third son of Archibald Alexander, Joseph Addison Alexander (1809-1860) graduated at the College of New Jersey in 1826, having devoted himself especially to the study of Hebrew and other languages. From 1830 to 1833 he was adjunct professor of ancient languages and literature at the College, and then moved to Princeton Theological Seminary as an assistant to Charles Hodge, professor of oriental and biblical literature. In 1838 Alexander became associate professor, and succeeded Hodge in that chair in 1840. He transferred in 1851 to the chair of biblical and ecclesiastical history, and in 1859 to that of Hellenistic and New Testament literature, which he occupied until his death. The Trust publishes his Commentary on Acts, in the Geneva series.