The Treaty with the Delawares (also called the Treaty of Fort Pitt) was signed on September 17th, 1778 between the Lenape—or Delaware Indians—and the newly formed United States of America. It was the first of 374 ratified treaties between Native Americans and the government of the United States.
The treaty itself consisted of six articles. The first article called for the mutual forgiveness of all past hostilities. The second and third articles established a “perpetual peace and friendship” with an obligation of each party to assist the other in any “just and necessary war.” Specifically, the third article makes mention of the current war between the United States and the King of England (the Revolutionary War), giving American troops free passage through Delaware territory. The fourth article pertains to preserving the “security of the peace and friendship” by forbidding either party to inflict punishment on the other without just trial nor protect any enemy of the other. The fifth article established trade between the United States and Delaware nation. Finally, the sixth article solidifies the treaty by guaranteeing the “nation of Delawares, and their heirs, all their territorial rights in the fullest and most ample manner” as well as allowing the Lenape to form a confederation of tribes of which they are the head and have representation in Congress.
There is no ambiguity in this treaty about the sovereignty of the Delaware. In fact, this treaty represents the recognition by the Lenape of the newly formed—and still quite weak—government of the United States.