Joseph Priestley, born in 1733 and dead in 1804, was a Unitarian minister, teacher, author, natural philosopher, discoverer of oxygen, and friend of Benjamin Franklin and Thomas Jefferson. He supervised the construction of this house and laboratory from 1794 to 1798, then lived and worked here until his death in 1804. His library of some 1,600 volumes and his chemical laboratory, where he first isolated carbon monoxide, were probably the best in the country at that time. As Edgar Fahs Smith suggested in 1920, the Joseph Priestley House became "a Mecca for all who would look back to the beginnings of chemical research" in America.