This town (now called Portland) is notable for being the site of the negotiation and signing of the Treaty of Casco 1678, the document which is often used to demarcate the end of King Philip's War. It was negotiated between colonist representatives Major Shapleigh, Captain Champernoon, and Mr. Fryer of Portsmouth, Sokiki sachem Squando, and several other Indian chiefs whose names have since been lost to history. Ironically, it is highly unlikely that any Pokenoket were involved in the negotiation and ratification of this treaty. The English colonists had an active bounty on any Pokenoket over the age of 14 at that point, making it very unlikely that any Pokenoket would step forward to participate in negotiation with the English and be allowed stay alive and in the area long enough to impact its terms.
Although it marked a significant reduction in violence between the colonists and the indigenous people who settled in the New England region before them, it was not the end of conflict between the colonists and the tribal nations in the area. It promised the members of the Wabinaki Confederacy reinstated sovereignty over the lands settled by English colonists in the Maine region and regular payments of corn from the colonists as reparations in exchange for allowing the colonists to remain living where they settled as property owners. The promises would seem to favor the Wabinaki, and yet the colonists failed to honor the spirit of the agreement. They continued to make new settlements on the lands they allegedly gave control of to the Wabinaki Confederacy, and continued destructive habits, like allowing colonist livestock to devour Indian cornfields, that drove many Wabinakis to leave the lands in the first place. Several more agreements, like the Treaty of Casco 1703, came after this treaty, but none were ever fulfilled to the satisfaction of all parties involved.
Unfortunately, no copies of the Treaty of Casco 1678 survive today. The closest thing to a surviving copy that historians have to work with is a brief summary of its terms and context on pages 158-159 of The History of New-Hampshire.: Volume I. Comprehending the Events of One Complete Century from the Discovery of the River Pascataqua. by Jeremy Belknap, originally published in 1792. It is scant on details, but from his characterization of the treaty as "disgraceful, but not unjust," it is apparent that the colonists strongly resented the concessions they made in the Treaty of Casco 1678, yet also recognized that those concessions were not unreasonable given the colonists' poor conduct on lands that had long been occupied and used by other societies and family units before the colonists showed up.