McMillan arrived in Mt. Pleasant on 3 March 1875. The postmaster in Mt. Pleasant, Jeremiah Page, approached McMillan about the possibility of establishing a school for the children of roughly thirty apostate Mormon families. Once McMillan had discussed the matter with the families, it was agreed that McMillan would be given title to a building secured by a mortgage and the claims of the stockholders and that he would assume any debts. He also was required to furnish the school and arrange the necessary curriculum. The school officially opened on 19 April 1875. The enrollment upon opening consisted of 44 students and grew to 109 by the end of the term.
In the beginning, McMillan found difficulty in meeting his financial obligations regarding the property; and he asked the Presbyterian Church in Salt Lake City for help. It suggested that he deed Liberal Hall, his name for the building, over to the trustees of the church in Salt Lake City. A sum of five hundred dollars was sent to him, securing the real estate. He then initiated his educational plans, hiring a Miss Delia R. Snow as the schools first teacher. Besides Miss Snow, he hired many women, as he felt that they were more successful in teaching than were men. Among the earliest women educators at Wasatch Academy were Miss Alice C. Sowles, Mrs C.J. Wilcox, Miss Maria Fishback, and Miss Clara Pierce.
During the early years, the academy was a grade school. In 1880 the school came under the direction of the Board of Home Missions, and classes were held in Liberal Hall until 1891. In that year, a new two-story brick structure was constructed. The cost was approximately $10,000 and the money for its construction was donated by the Ladies Missionary Society of the Synod of New York. By 1887 Wasatch Academy had reached true academy status; classes were taught in rhetoric, mathematics, government, bookkeeping, history, physiology, Latin and physics. In 1894, with an enrollment of 120 students, George Marshall became principal. He served until 1905, and during his tenure a boarding unit was added to provide students from other areas to attend Wasatch. Ernest Patterson became principal in 1905. He was succeeded in 1908 by Walter McKirahan, and the school's administration building was erected at that time. In 1911 Charles L. Johns became principal. Johns enlarged the school, adding several buildings including a boys dormitory, and a hospital.
In 1912, because of the opening of the public school system in Utah, Wasatch Academy changed its direction. It became a college preparatory school and remains as such to this day. The school has always maintained a low student/teacher ratio. At present it is one teacher for every eight students, which allows for individual attention to each of the students in the program. Enrollment at Wasatch Academy has remained relatively constant at about 125 students. At the present, prospective students must submit an application with excellent references to be considered for admission. In addition, at the school students are required to do additional tasks in a family type setting. These include domestic chores and religious responsibilities. Students and faculty live in a close association; they eat together and students study in a dormitory environment with the help and direction of the teachers.
Since 1972 Wasatch Academy has been an independent, interfaith school. Located on fourteen acres, the school includes historic brick buildings that house classrooms, a gymnasium, dormitories, a large playing field, homes for faculty and a museum. To meet the student's emergency`and routine medical needs, a clean, modern and professionally staffed hospital is located only one mile away.
Some goals of Wasatch Academy have changed since its beginnings. The original reason behind the establishment of Wasatch Academy, to provide for an alternative to Mormon culture, is no longer cogent. Students today attend the school for a variety of reasons including academic excellence and culture lifestyle. The academy, accredited by the Northwest Association of Schools and Colleges since 1939, is a member of the National Association of Independent Schools and the College Board. It is one of eleven such schools currently administered by the Presbyterian Church throughout the contiguous United States.
Wasatch Academy has developed into an excellent academic preparatory school. Approximately 75 to 90 percent of the school's graduates go on to colleges or universities. Extracurricular activities, including skiing, soccer, music, arts, baseball, and swimming, are offered. Currently, Doctor Joseph Loftin, headmaster, continues the tradition established in 1875 by Dr. Duncan McMillan, who said, "Let it endure like the Wasatch Mountains...call it Wasatch Academy."