In 1783, while Congress was meeting at Nassau Hall in nearby Princeton, Rockingham was rented from Margaret Berrien, widow of New Jersey Supreme Court Justice John Berrien, for the use of General George Washington, and it served as what became his final wartime headquarters from August 23 to November 10, 1783. More than 100 years later, in 1896, Mrs. Josephine Thompson Swann and Miss Kate E. McFarlane joined other concerned citizens to save the house from demolition. Long known by area residents as the old Berrien Mansion, the 18th-century farmstead had hosted a number of Revolutionary War dignitaries, but had fallen into disrepair and was being used as temporary workers' housing for those employed by Howell Quarries of Rocky Hill. Through a generous gift by Mrs. Swann, who agreed to pay the asking price, the mansion was saved, became the property of the new Washington Headquarters Association, and was moved to a new location. The oldest section of Rockingham was built about 1710 in a saltbox style, enlarged in the 1760s, and later given a two-story porch and large attic in the early 19th century. It stands today at its fourth location, about one mile south of its original site, and is now administered by the New Jersey Department of Environmental Protection, Division of Parks and Forestry. Kate McFarlane and Josephine Swann were recognized for their determined effort to save Rockingham, a significant site with an important role in the Revolutionary War, and for their place in women’s historic preservation in New Jersey.