Jacob Arnold's Tavern, also known as the Old Arnold Tavern and the Duncan House, was a "famous" historic tavern established by Samuel Arnold circa 1740. Until 1886, it was located in Morristown Green in Morristown, New Jersey. In 1777 it served as George Washington's headquarters during the Revolutionary War, and it was the site of Benedict Arnold's first trial in 1780. The National Park Service claims "Much of [Morris]town's social, political, and business life was conducted at Arnold's Tavern" during the Revolutionary era.