It all started when...

On April 19, 1882, the "New England School", yet unnamed, opened its doors. The following year in 1883, the school was named South Lancaster Academy.

In 1885, the school expanded to include college preparatory courses. Teacher training was added in 1886, with the development of a "normal school", the J. T. Browning Missionary and Industrial School.

In 1918, its standing as a junior college was formally recognized and the school name was changed to Lancaster Junior College.

In 1922 degree-granting powers were conferred by the Massachusetts legislature. The school's college level separated and name was changed to Atlantic Union College with the school beginning to operate on the senior college level, offering a four-year theological course. The college became a separate institute from South Lancaster Academy and the academy having its own board of trustees and faculty.

Since 1967, South Lancaster Academy has been a twelve-grade school. Preschool, Pre-kindergarten, and Kindergarten were added to the program in subsequent years. The academy attempts to maintain the historic ideals of Seventh-day Adventists on matters of morals, dress, and conduct, as its reasons for existence. South Lancaster Academy is operated by the SDA churches of Atlantic Union College, Leominster, South Lancaster Village, and Sterling. South Lancaster Academy is also operated by the Southern New England Conference of Seventh-day Adventists and the Atlantic Union Conference of Seventh-day Adventists.