Henry Phillips was a third generation Phillips family member in Pleasant Valley; his grandfather arrived in 1737. Ca, 1805, Henry constructed the stone section of the house on the land he inherited from his father. Ca, 1830, he added the large frame addition to the east. The rear section was added to the north of the original house by the farm's subsequent owner, Charles Miller in 1865. Following Miller's tenure many different families occupied the farm including the Cromwells who ran it as a dairy farm for almost 30 years. In 1874, Inez Howell donated the farm to Mercer County. The Henry Phillips House was listed on the New Jersey Register of Historic Places in 1976 and the National Register in 1977.
Funding for the restoration of the house has been made possible by the Mercer County Park Commission and by the Garden State Historic Preservation Trust Fund administered by the New Jersey Historic Trust/State of New Jersey.
The Mercer County Park Commission; Brian M. Hughes, County Executive, Kevin B. Bannon, Executive Director.