Treaty With the Delawares
The Treaty of Fort Pitt — also known as the Treaty With the Delawares, the Delaware Treaty, or the Fourth Treaty of Pittsburgh — was signed on September 17, 1778 and was the first written treaty between the new United States of America and any American Indians—the Lenape (Delaware Indians) in this case. Although many informal treaties were held with Native Americans during the American Revolution years of 1775–1783, this was the only one that resulted in a formal document. It was signed at Fort Pitt, Pennsylvania, site of present-day downtown Pittsburgh. It was essentially a formal treaty of alliance.