The Morris-Jumel Mansion also known as the Roger and Mary Philipse Morris House , located in Washington Heights, is the oldest house in the borough of Manhattan in New York City. It served as a headquarters for both sides in the American Revolution. It was built by Roger Morris in 1765 and reflects the Palladian style of architecture. Morris, the nephew of a successful English architect, was greatly influenced by the designs of the 16th-century Italian architect Palladio. His residence includes a monumental portico and pediment, supported by grand Tuscan columns, and a large, two-story octagonal addition at the rear. The octagon room is believed to be the first in the country..