The first formal written treaty between the…
September 1778 CE
The first formal written treaty between the United States and a Native American tribe (the Lenape or Delaware), the Treaty of Fort Pitt, is signed on September 17, 1778.
Although many informal treaties have be and will be held with Native Americans during the American Revolution years of 1775–1783, this is the only one that results in a formal document.
It is signed at Fort Pitt, Pennsylvania, site of present-day downtown Pittsburgh.
Essentially a formal treaty of alliance, the treaty gives the United States permission to travel through Delaware territory and calls for the Delawares to afford American troops whatever aid they might require in their war against Britain, including the use of their own warriors.
The United States is planning to attack the British fort at Detroit, and Lenape friendship is essential for success.
In exchange, the United States promises "articles of clothing, utensils and implements of war", and to build a fort in Delaware country "for the better security of the old men, women and children ... whilst their warriors are engaged against the common enemy."
Although not part of the written treaty, the commissioners point out the American alliance with France and intend that the Delaware will become active allies in the war against the British.