James Renwick, Jr.
James Renwick, Jr. CC 1836 MA 1839 was a gothic revival architect. He designed St. Patrick's Cathedral, the Smithsonian Castle, and the original home of St. A's.
Renwick entered Columbia at age twelve, and went on to earn a graduate degree here. His father, James Renwick, was also an architect and engineer, and served as a professor of "natural philosophy" at Columbia College.