The New Castle Court House, located in the heart of the historic City of New Castle, Delaware, is one of the oldest surviving courthouses in the United States and a registered National Historic Landmark and is also part of Delaware's First State National Historic Park. The original 1732 court is built over the remains of the 1660s courthouse, with additions and modifications throughout the 18th and 19th centuries. All jurisdictions of Delaware's courts, and including the federal courts, have met in this building. The New Castle Court House was also Delaware's first capital building and meeting place for the colonial and first state Assembly. On June 15, 1776, the legislature passed a resolution to separate from Pennsylvania and Great Britain, creating the State of Delaware. The Court House cupola was designated in 1732 as the center of the 12-mile circular boundary, which created Delaware's unique curved northern border. Significant events took place at the New Castle Court House involving slavery and the Underground Railroad, including the trials of abolitionists Thomas Garrett and John Hunn. In 2003, the New Castle Court House was designated as a National Historic Underground Railroad Site by the U.S. Department of Interior and awarded inclusion in the Nation Park Service Network to Freedom Program.