Treaty with the Delaware, 1778

...if either of the parties are engaged in a just and necessary war with any other nation or nations, that then each shall assist the other in due proportion to their abilities...
...for the better security of the old Men Women and Children of the aforesaid nation...it is agreed on the part of the United States, that a fort of sufficient strength and capacity be built...

The United States did not fulfill its promise to build fortifications for protection of the Delaware. Within a year, most Delaware had switched their allegiance to the British.
...form a state whereof the Delaware nation shall be the head, and have a representation in Congress...

This unique article suggests that the Delaware tribe could form a new state and be represented in Congress; however it is not clear that such a a proposal was ever submitted.

Treaty with the Delaware 1778

The treaty with the Delaware, shown here, is the first treaty between the United States and a Native American tribe. It is also the only one signed by the Continental Congress.

National Archives, General Records of the U.S. Government