the colony. When Philipse died in 1702, the manor was divided between his son, Adolphus Philipse, and grandson, Frederick Philipse II. Adolphus received the Upper Mills property, which extended from Dobbs Ferry to the Croton River. Frederick II was given the Lower Mills, which included the family seat, Philipse Manor Hall, at the confluence of the then Neperhan River (today's Saw Mill) and Hudson Rivers; the two parcels were reunited on his uncle's death. Frederick II's son, Frederick III, became the third lord of the manor in 1751. The Philipses used slaves to build various structures at the Upper and Lower Mills. The Upper Mills saw the building of two gristmills on the Pocantico River as well as a stone manor house, wharf, cooperage, and bake house. Most of the structures were completed by 1697, including the Old Dutch Church of Sleepy Hollow, now a National Historic Landmark. The Lower Mills saw a gristmill and Philipse Manor Hall built on the north bank of the Neperhan. The Philipses' aim was to make the manor a center for agriculture, which was achieved. In the 18th century, tenant farmers moved in from Great Britain, the Netherlands, France, Germany, and elsewhere within North America. By the beginning of the American Revolution in 1776, the population was about 1,000, up from 200 at the time of Frederick I's death. Several years into the Revolution Frederick Philipse III, a Loyalist, was attainted for treason along with his family. The manor was confiscated in 1779 and used as collateral to raise funds for the Colonial cause. After the war it was sold at public auction, split between 287 buyers. The largest tract, the (about ) Upper Mills, was purchased by Gerard Beekman; the lower, including Manor Hall, went to Cornelius Low. That parcel was passed to numerous owners until 1951, when it was acquired by Sleepy Hollow Restorations (now Historic Hudson Valley). Philanthropist John D. Rockefeller Jr. funded the restoration of about , which became today's Philipsburg Manor historic site. Philipse Manor Hall served as Yonkers City Hall from 1872 until 1908. Both homes became National Historic Landmarks on November 5, 1961 and are now house museums. Legacy In 2004, it was added to the African American Heritage Trail of Westchester County, a group of 14 sites which include the Rye African-American Cemetery, Saint Paul's Church National Historic Site and the Jay Estate. See also Land