Hackley School is a private college preparatory school located in Tarrytown, New York, and is a member of the Ivy Preparatory School League. Founded in 1899 by a wealthy philanthropist, Frances Hackley, Hackley was intended to be a Unitarian alternative to the mostly Episcopal boarding schools throughout the Northeast. Since its founding, Hackley has dropped its Unitarian affiliations and changed from all-boys to coeducational. Hackley is divided into three schools on the same campus: the Lower School, the Middle School, and the Upper School. Hackley school is also a member of global education association, Round Square. In September 2015, Hackley announced the appointment of Michael C. Wirtz as Hackley's 12th head of school. Wirtz began his tenure July 1, 2016, succeeding Walter C. Johnson, who served as headmaster from 1995 to 2016. History Founding During the 1890s, the American Unitarian leadership in Boston became increasingly concerned about the lack of Unitarian presence in secondary and college preparatory education. Unitarians controlled Harvard University; its president, Charles Eliot, was the leading lay-person in the Unitarian movement, and the faculty included numerous Unitarians. Frances Hackley, a wealthy widow and leading supporter of the Unitarian movement, decided to give her summer mansion in Tarrytown to a charity. She resided in New York City, and was a member of the Church of the Messiah. Hackley was friends with the church's minister, who proposed using the mansion as a school for boys. In the winter of 1898–1899, she met with Samuel Eliot of Boston, who later became the president of the American Unitarian Association, and several other prominent Unitarians. Hackley liked the idea of a college preparatory school to serve the Unitarian community and any families interested in a liberal religious environment and wanted to use her home for this purpose. She provided substantial funding to refurbish the mansion for school purposes and to operate the school for several years. In the spring of 1899, a board of trustees was formed and very shortly thereafter it selected its first headmaster. The first students arrived in the autumn of 1899 and resided in the Hackley home, today called Hackley Hall. Hackley School celebrates Frances Hackley's birthday, October 27, as "Founders Day" to this day. Expansion The home and grounds quickly proved inadequate to support a preparatory school. In the fall of 1899, Theodore Chickering Williams and Seaver Buck, the first headmaster and the first master hired, respectively,