Bay Ridge’s Adelphi Academy was founded in 1863 by two teachers from the Brooklyn Polytechnic Institute, Aaron Chadwick and Dr. Edward S. Bunker, and opened on Fort Greene’s Adelphi Street, a name that comes from the Greek term for “brotherhood” (cf. “Philadelphia,” or “brotherly love”). Brooklyn’s Adelphi Street in turn had been named for London’s Adelphi Terrace, an early housing development in London, England that lasted from 1774 to 1938.
In 1965 Adelphi moved to a large brick mansion that was previously the Kallman Home for Children at Ridge Boulevard and 86th Street. The school expanded with a new gym in 1978 and an adjoining five-story classroom building in 1990.