Built in 1777, the Hessian Powder Magazine is a stone walled structure, which is lined with interior brick. It measures seventy feet by thirty-two feet with walls that are four-and-one-half-feet thick. It also has a vaulted stone roof, which is covered by timbers and tin, creating a gable form. Tradition says that
Hessian prisoners of war, who were captured during the
Battle of Trenton were sent to Carlisle, and used to build this guard house, which was originally a magazine. It may have first been used as a guardhouse during the 1870s, and also as part of the
Carlisle Indian Industrial School (1879–1918). Afterwards, it was used as a
quartermaster and medical supply storehouse,
filmstrip laboratory, message center, and U.S. post office. == Importance ==