Referred to as "the most important institution of its kind in the world" by Shoghi Effendi, the Guardian of the Bahá'í Faith, Green Acre occupies a unique place in history.
Built in 1890, Green Acre originally served as the Eliot Hotel. Sarah Jane Farmer, a partner in the hotel, was the daughter of prominent transcendentalist and inventor Moses Gerrish Farmer and philanthropist Hannah Shapleigh Farmer.
Sarah Farmer conceived Green Acre as a gathering place where minds, souls, and bodies would be refreshed. After meeting with participants in the Parliament of Religions in Chicago in 1893, she pursued the opportunity for Green Acre to become a universal platform for the comparative study of religions and in 1894 opened Green Acre with the raising of the world's first-known "peace" flag. Sarah had chosen the theme of peace for Green Acre because she believed it represented a call to all humanity as well as the message brought by each prophet.
In 1899, Sarah Farmer had the privilege of being in the presence of ‘Abdu’l-Bahá, son of Baha’u’llah, the Prophet-Founder of the Bahá’í Faith and the Center of His Covenant, in the Holy Land and found complete fulfillment of her ideas of social reform in the Bahá’í Teachings. She returned to America with a vision that Green Acre would become a center for truth, peace, and justice.
From 1900 to 1909, Green Acre provided a focal center for the development of the early Bahá'í community, and with Sarah’s initiative, became the first Bahá’í summer school. ‘Abdu’l-Bahá visited in 1912, conferring upon Green Acre another unique distinction as the only school imbued with the spirit of His presence.
Later, in 1926, Green Acre came under the direct supervision of the National Spiritual Assembly of the Bahá'ís of the United States, which was elected at Green Acre for the first time in 1925. Both Sarah Farmer and William Henry (Harry) Randall, her successor administrator of Green Acre, were named Disciples of 'Abdu’l-Bahá by Shoghi Effendi.
Green Acre continues in its development as a center of learning devoted to the advancement of a spiritual and material civilization.