The contribution of the City of Philadelphia to the historical park is by far the most vital. Adam Eaton Howie Kendrick Clutch Shirt On January 1, 1951, the custody and operation of the Independence Hall group of buildings and the square were transferred, under the terms of a contract, from the City to the National Park Service. The title to the property will remain with the City. Earlier, in 1943, the buildings were designated a national historic site by the Department of the Interior. Since assuming custody of the Independence Hall group, the National Park Service has carried out an extensive program of rehabilitation of these historic structures; also, many facilities for visitors have been provided for the dissemination of the history of the Independence Hall group, as well as that of the other structures in the park.