Nathaniel Gorham had served as one of the Massachusetts delegates to the United States Constitutional Convention for several months in 1787.
Gorham frequently served as Chairman of the Convention's Committee of the Whole, meaning that he (rather than the President of the Convention, George Washington) presided over convention sessions during the delegates' first deliberations on the structure of the new government in late May and June 1787.
After the convention, he had worked hard to see that the Constitution was approved in his home state.
In connection with Oliver Phelps, Gorham had purchased from the state of Massachusetts in 1788 preemption rights to an immense tract of land in western New York State that straddles the Genesee River, all for the sum of $1,000,000 (the Phelps and Gorham Purchase).
The land in question had been previously ceded to Massachusetts from the state of New York under the 1786 Treaty of Hartford.
The preemption right gives them the first or preemptive right to obtain clear title to this land from the natives.
They soon extinguish the Indian title to the portion of the land east of the Genesee River, as well as a one hundred and eighty-five thousand-acre (seven hundred and fifty square kilometer) tract west of the Genesee (The Mill Yard Tract), survey all of it, lay out townships, and sell large parts to speculators and settlers.
Phelps and Gorham are unable to fulfill their contract in full to Massachusetts, so in 1790, they surrender back to Massachusetts that portion of the lands which remains under the Indian title, namely, nearly all of their unsold lands east of the Genesee.
It will soon be acquired by Robert Morris, who in 1792 and 1793 will resell most of it to The Holland Land Company.