1949:

The Lower School buildings in Cambridge are sold, ending the school's link to Cambridge.

1951:

Marion Aldophus (Dolph) Cheek takes the helm as head of school. For the next seventeen years, Cheek's dynamic energy and imagination lead the school into a renaissance period of growth and expansion. During those years, the school doubles its enrollment from 128 to 300, and expands the campus with a new library, student union, science wing, New Boy's dormitory, and dining hall.

1953:

Students begin building the Science Wing, a project that is completed in 1956. This same wing serves as the current physics and chemistry labs.

1972:

The Caroline Crosby Field Student Union is transformed into the Art Center (the present day Art Building). The first End-of-Mod Art Show is held in the new center.

1972:

Ziskind Dining Hall burns in an accidental fire. Within months, it is replaced with a passive solar-heated building designed by Norman Saunders, a pioneer in passive solar design.

1973:

The groundbreaking Module System is launched by Head of School Bob Sandoe. Classes are expanded to one and a-half hours long, and the school year is divided into seven, five-week modules. The system allows for intense, in-depth study, as well as flexibility for off-campus projects and internships. The same year launches two signature off-campus programs: the Marine Biology course at Woods Hole, and the Wilderness Program.