Date: Signed 1783
This is the treaty that ended the war between Britain and the United States. (Not to be confused with the Treaty of Paris of 1763, which ended the French and Indian war, or the Treaty of Paris of 1810, which ended the French war with Sweden. Paris loves a treaty.)
The fighting between American and British forces had mostly ended by 1781, with Cornwallis' surrender at Yorktown. This agreement formalized the end of the war, and declared the United States as a new nation, with the 13 colonies as 13 new states.
The treaty also provided for the release of prisoners of war on both sides, a return of seized property to Loyalists and Patriots alike, and and expansion of the boundaries of the United States. Of course, the reality was a bit more complicated - both sides refused to return property that theoretically belonged to the other, like a messy divorce and some easy listening CDs. And as to the offer of expanding territory - well, Spain had other ideas about whose land it was - as did the Indigenous peoples living their.