On June 28, 1948, Congress passed Public Law 795, H.R. 5053 to authorize the creation of Independence National Historical Park, and it was formally established on July 4, 1956. On March 16, 1959, it incorporated the "Old Philadelphia Customs House" (Second Bank of the United States), which had been designated a national historic site on May 26, 1939. As with all historic areas administered by the National Park Service, the park was listed on the National Register of Historic Places on October 15, 1966. In 1973, the Pennsylvania legislature voted to transfer the three blocks that compose Independence Mall to the federal government. Independence Hall was designated a UNESCO World Heritage Site on October 24, 1979.