Two brothers who were Episcopal clergymen - The Reverend Theophilis M. Reilly, and the Reverend William M. Reilly, conducted St John's Academy in Burlington. In 1871 they moved the school to Haddonfield when they purchased 110 acres that were part of the high ground at 310 Centre Street.
In 1878 a sister school for girls, St Agnes Academy, was founded. It was housed opposite to the boys' school on the corner of Lakeview Avenue and Centre Street. Both schools were under the direction of Mrs. William M. Reilly.