Officially, Casady School began as Casady Hall. Bishop Thomas Casady had in hand assets originally intended for the diocesan center. A gift from Edward J. Miller of propery located at the corner of Britton Road and Pennsylvania Avenue would provide the campus and first buildings for the School. This included a tract of 38 acres of land, a small lake, a house, and two barns. Reportedly, Bishop Casady was reluctant to have the school bear his name; he preferred that of a saint rather than a "living sinner." He was, however, unanimously overruled by the board.
The Rev. Michael Martin served as Casady's first headmaster from 1947-1952.
The Rev. Michael Martin was hired as headmaster and Casady Hall opened its doors to students for the first time. There were thirty-six students in three grades - seventh, eighth, and ninth - and a faculty of four. Classes were held in the remodeled pony stable, which had been christened Cochran Hall. The feed building behind Cochran became appropriately known as the "Snack Shack."
Through the generosity of Frank Johnson Hightower and as a memorial to his parents, the Chapel of St. Edward the Confessor was constructed, completing another aspect of Bishop Casady's overall plan for the campus. Ever since, the chapel has been the spiritual center of Casady School. More than six hundred daily services as conducted during the school year, involving students of every age.
Built during the summer of 1948 to accommodate the increasing enrollment of the School. It was named in honor of Walter E. Allen.
Named after an original member of the Board of Trustees, L.C. Griffith. Griffith Hall originally housed the School's kitchen and dining hall. It was used for an array of functions in that time, like dances, study hall, and theatrical performances. Currently it is the location of the Upper Division offices, student center, and sophomore lockers.
Casady has its first graduation for the five students in the Class of 1951.
The Hightower Building originally housed science labs, and is now home of the Upper Division English and History departments. Miller was originally used for humanities and language course, and today houses the Upper Division Modern and Classical Languages department.
Shaun Kelly, Jr. served as Casady's headmaster from 1952-1956.
