The 2018 New Jersey History
and Historic Preservation Conference
The Dey Mansion was constructed during the second half of the eighteenth century and is an excellent example of high-style Georgian architecture. The building is also significant for its association with the Dey family, an important Passaic County family. Additionally, the building derives significance from its association with George Washington, who used the building as his headquarters on two occasions in 1780. The mansion was acquired by the Passaic County Park Commission in January of 1930. It was restored under the supervision of Charles Over Cornelius, architect and former associate curator of decorative arts at the Metropolitan Museum of Art. It has been open to the public as a house museum since 1934. The building has gained significance as an early example of preservation in New Jersey.