The city of Allentown, Pennsylvania, was established in 1762 and is one of the oldest major cities in the Commonwealth of Pennsylvania and the United States. It has deep roots in the history of the nation; it was the hiding place of the Liberty Bell during the American Revolution, and its oldest city cemetery has graves of patriots who served in the Continental Army. Over its 250-year history, many people and things have played a part in the history of the city; numerous buildings, bridges, parks and other locations in the city have come and gone, but many remain, with thirteen of them being on the National Register of Historic Places.