Given the following context:

The Iroquoian-speaking Susquehannocks were the earliest recorded inhabitants of the West Branch Susquehanna River basin, which includes Quehanna Wild Area. They were a matriarchal society that lived in stockaded villages of large long houses. The Susquehannocks' numbers were greatly reduced by disease and warfare with the Five Nations of the Iroquois, and by 1675 they had died out, moved away, or been assimilated into other tribes. After this, the Iroquois exercised nominal control of the lands of the West Branch Susquehanna River valley. They also lived in long houses, primarily in what is now New York, and had a strong confederacy which gave them power beyond their numbers. To fill the void left by the demise of the Susquehannocks, the Iroquois encouraged such displaced eastern tribes as the Shawnee and Lenape (or Delaware) to settle in the West Branch watershed.The Seneca tribe of the Iroquois hunted in much of Pennsylvania and the Quehanna area. The Iroquois and other tribes used the Great Shamokin Path, the major native east–west path connecting the Susquehanna and Allegheny River basins, which passed south of what is now the wild area. The native village of Chinklacamoose (or Chingleclamouche) was on this path at the West Branch Susquehanna River, at what is now Clearfield to the southwest of Quehanna. The Sinnemahoning Path along Sinnemahoning Creek ran north of Quehanna; as the path with the gentlest grade, it may have been the route the first Paleo-Indians took entering this part of Pennsylvania from the west.The French and Indian War (1754–1763) and the subsequent colonial expansion encouraged the migration of many Native Americans westward to the Ohio River basin. In October 1784, the United States acquired a large tract of land, including what is now Quehanna Wild Area, from the Iroquois in the Second Treaty of Fort Stanwix; this acquisition is known as the Last Purchase, as it completed the series of purchases from the resident Native American tribes of lands within the boundaries of...

answer the following question:

What was the acquisition acquired from the Iroquois in the Second Treaty of Fort Stanwix called? 

Last Purchase