Built in 1765, the Morris-Jumel Mansion stands as the oldest house on Manhattan Island. During the year 1776, it served as the headquarters for George Washington. Today, this historic building has been transformed into a museum surrounded by a 1.5-acre park. Visitors can explore a decorative arts collection that showcases pieces from the colonial and Revolutionary War periods. Among the 12 meticulously restored rooms, Washington's former office remains a highlight.
Source - https://en.wikipedia.org/wiki/Morris%E2%80%93Jumel_Mansion