Sarah Langley was born in Hingham on April 18, 1714 to John and Hannah (Vickery) Langley. The first and only surviving child of the Langley's, Sarah grew up on the corner of Town Street and Fish Lane (now North Street and Ship Street). Sarah's father owned Langley's Island and a small boat yard, but most of the family's income was from the inn they ran at their homestead. Although there were few travelers to Hingham, the tap room was frequently used by local residents.
Sarah Langley grew into a very attractive young woman and had many suitors. She chose to marry Ezekiel Hersey, a doctor and Harvard College graduate, who came from a very wealthy family. They became husband and wife on July 30, 1738 - the same year in which Sarah's father died. Sarah went to live with her husband in the Hersey homestead, known as the "Mansion," located on the old Boston Post Road. While her husband concentrated on his profession, Sarah managed all the affairs of the large estate.
Ezekiel died on December 9, 1770 at the age of 61 and left his estate to his wife. He did however, request that she donate 1,000 pounds to Harvard College to create a position for a Professor of Anatomy and Physiology. She made the donation, and the first step was taken toward establishing a medical school at Harvard College.
Ten months after Ezekiel's death Sarah married Captain Richard Derby, a prominent resident of Salem, Mass. After their marriage Sarah moved to his home in Salem, where she lived for twelve years. As she had in Hingham, Sarah became a well-known figure in local society, attending events and holding social gatherings. After Richard Derby died in December of 1783 Sarah, who was 69, returned to her first husband's home in Hingham.
Sarah was unable to receive an education as a child not only because she was female, but also because her family was not wealthy. As a wealthy adult, she wanted to ensure that future generations of girls would have the opportunity to do what she could not. In October of 1784 she signed the paperwork required to created the first coeducational school for lower and middle-class children in the country.
The school was to be managed by ten trustees, including Rev. Ebenezer Gay and General Benjamin Lincoln. Upon her death they would receive a piece of land on Main Street along with the town houses, barn, and outhouses located on it. They were to use this property to open and maintain the school.
Sarah Derby died on June 17, 1790, leaving money to many different groups and organizations, including Old Ship Church and Harvard College. Derby Academy was opened in 1791, and quickly gained a national reputation as a quality school for both boys and girls. It still exists today as the oldest independent school for both boys and girls.