Original Location and the Colonial Period
Rockingham is believed to be the second oldest house in the Millstone River Valley, its original rooms built between 1702 and 1710. The house was originally a two-story, two-room frame house situated high on a rocky hillside above the river. When the house was purchased by John Berrien, a prominent New Jersey Supreme Court Judge, in 1735, he greatly enlarged it for his growing family, making it a substantial farm appropriate for a wealthy, educated man.

In 1783, the Philadelphia troops of the Continental Army went into revolt and marched upon Philadelphia. Congress fled to Princeton, New Jersey, after being assured of the city's loyalty. Elias Boudinot, President of the Continental Congress, called upon General George Washington to send a loyal detachment of troops and requested his presence. When Washington arrived and tried to get lodgings in Princeton , he ran into unforeseen difficulties. The owners of many of the best homes in Princeton would only agree to rent to Washington for a full year. The only suitable home sat four miles away and belonged to the widow of John Berrien. Mrs. Margaret Berrien agreed to rent Rockingham to the General and his entourage on a monthly basis. On August 23rd of 1783, General Washington - accompanied by his wife, a small guard of 12 to 24 men, and servants - took up residence.

The General would ultimately stay there for almost three months, from August to November. It must have been a pleasant stay with Rockingham's varied orchards and spacious grounds, although Mrs. Washington was ill and returned to Mount Vernon. Washington entertained frequently, including various dignitaries such as Jefferson and Madison and hosted at least one party with over two hundred guests.

On October 31st, Washington received word that the Treaty of Paris had been signed, effectively ending the Revolutionary War. It was on November 2nd, 1783, that Washington wrote his Farewell Orders to the Armies, giving thanks and praise to his troops. On November 10th Washington and his troop of 20-25 soldiers left the farmstead.

Into the 19^th and 20^th Centuries - The First Two Relocations of the Mansion

Sometime after Washington's occupancy, Mrs. Berrien moved back into her home. No buyer appeared until 1802, when she finally sold the farm to Frederick Cruser. Rockingham stayed within the Cruser family until its sale in 1841. The buyer, David H. Mount, had large landholdings on the west side of the Millstone River in Rocky Hill. Three years later, Mount sold several parcels of land to Martin A. Howell. Howell began to quarry the hill that Rockingham sat upon. By 1896, the Rocky Hill Quarry Company had expanded to such a degree that most of the hill on which the house stood was gone.

The house itself had fallen into great decline. In 1896, the quarry turned the mansion into housing for Italian quarrymen and their families, with several families living in each room.

At this point, the decline of the old house came to the attention of Kate McFarlane of Rocky Hill; she became determined to save it and enlisted the help of Mrs. Josephine Thomson Swann. Money for restoration and great enthusiasm came to the rescue and, in 1897, the newly formed Washington Headquarters Association of Rocky Hill purchased the house from the quarry for the sum total of $1.00. The house was then moved further up the hill away from the advancing quarry operations.

In 1956, by then owned and operated by the State of New Jersey, Rockingham was once again moved away from the encroaching quarry and the damage of the accompanying blasts.

The 21^st Century and Final Move

Today Rockingham continues to be operated by the State of New Jersey, Division of Parks & Forestry, greatly aided by the site's official friends group, The Rockingham Association (est. 1961). And once again, expansion of the quarry led to Rockingham's third and final move in July, 2001, to a much larger site along the Delaware and Raritan Canal, closer to its original location.

The mansion was restored and reopened to the public in 2004. Thousands of people from all fifty states and abroad visit every year and attend the varied programs offered at the site.