By 1883, The Chestnut Street Seminary was one of the most successful finishing schools in the country, and expansion was inevitable. Jay Cooke, Civil War financier and owner of a nationally-renowned estate in Elkins Park known as Ogontz, offered to rent his vacant five-story mansion to the principals of The Chestnut Street Seminary for the sum of $15,000 a year. Impressive ceremonies accompanied the school’s move—a day of addresses, music, and jubilation.
The mansion, with its many spacious rooms, could accommodate one hundred students. “Dignified, but not gloomy,” it came furnished in ornate Victorian style with heavy velvet carpets on the wide corridors. The large library became a classroom, and an amusement room on the top floor with a stage and seating capacity of 150 was used for lectures and plays. The Conservatory, a court with palms, rubber plants, and a sculptured fountain, was a central gathering spot. The elegance of the mansion proved impressive even to the affluent clientele. A lodge on the grounds would serve as a science laboratory, and new buildings were erected to accommodate an art studio, gymnasium, and music rooms. There also were stables, an infirmary, and greenhouses.