As the school’s population and reputation grew, so did its grounds. Having borrowed money to purchase the land on which the school is located on March 31, 1915, Miss Charlotte became the sole owner in 1918 by buying out her co-owner Major Hartley. From here Charlotte turned to the expansion of the academic and residential campus adding Sage House, donated by Mrs. Russell Sage; Spur and Spoon, the alumnae house; and the modern dormitories Court, Applegate and Dillon. In 1934 Covert, the home of the founder herself was rebuilt after having been destroyed by fire. The same year, Miss Charlotte announced her intention to give Foxcroft to her alumnae and she did just that in 1937. “Many women have had schools and made great successes of them,” said Miss Charlotte, “but I want mine to go farther than that. I want mine to go down through the ages, and that seems assured now.” The completion of The Schoolhouse in 1951 marked the last building funded by the first fundraising drive initiated in 1946 to boost Building and Endowment.
During these growing years the School bolstered its renown in the community and across the country. It graduated the first of almost 400 ITS (alumnae daughters and granddaughters) who would attend Foxcroft. It was paid a visit by the Duke and Duchess of Windsor and Miss Charlotte initiated Foxcroft Social Service as the beginning of the School’s commitment to community outreach. Miss Charlotte believed that involvement in the Social Service exposed her girls to “a cross section of the country and a part of life they have never seen before. It is impossible to tell the good that contact with these children does for Foxcroft and Foxcroft does for them.”