In 1716, a collection of law books belonging to the provincial government formed the first state library collection. After the State House was built in 1816, a room was set aside for the library. For a time, the Secretary of State also served as the State Librarian. In 1895, a separate building was constructed to house the State Library and the New Hampshire Supreme Court.
In1943, the State Library separated out its legal materials and created a Law Division of the State Library. It served as the Law Library for many years. In 1970, the current Supreme Court building was constructed, and the Law Division of the State Library moved, along with the New Hampshire Supreme Court, to the Supreme Court building.
In 1994, the legislature transferred administration of the Law Division of the State Library to the Judicial Branch, under the Supreme Court, thereby creating the New Hampshire Law Library.