 The French and Indian War ( 1754 – 1763 ) led to the migration of many Native Americans westward to the Ohio River basin . On November 5 , 1768 , the British acquired the New Purchase from the Iroquois in the Treaty of Fort Stanwix , including what is now Leonard Harrison State Park . The Purchase line established by this treaty was disputed , as it was unclear whether the border along " Tiadaghton Creek " referred to present @-@ day Pine Creek or to Lycoming Creek , further to the east . As a result , the land between them was disputed territory until 1784 and the Second Treaty of Fort Stanwix . After the American Revolutionary War , Native Americans almost entirely left Pennsylvania , although some isolated bands of Natives remained in Pine Creek Gorge until the War of 1812 . 
