Genesee Country, the farthest western region of New York State, comprising the Genesee Valley and westward to the Niagara River, Lake Erie, and the Pennsylvania line. The tract was a 3,250,000 acre portion of the Phelps and Gorham Purchase that lay west of the Genesee River. It was purchased from Robert Morris by the Holland Land Company. One of the provisions of the sale was that Morris needed to settle the Indian title to the land, so he arranged for his son Thomas Morris to negotiate with the Iroquois at Geneseo, New York in 1797. About 3,000 Iroquois, mostly Senecas, arrived for the negotiation. Seneca chief and orator Red Jacket was adamantly against the sale, but his influence was thwarted by freely distributed liquor and trinkets given to the women. In the end he acquiesced and signed the Treaty of Big Tree. The tribe sold their rights to the land, except for a small portion, for $100,000. Mary Jemison, known as The White Woman of the Genesee, proved to be an able negotiator for the tribe and helped win more favorable terms for them. The land was then surveyed under the supervision of Joseph Ellicott, the biggest land survey ever attempted to that time. Ellicott, as agent for the company, established a land office in Batavia in 1802. The entire purchase was named Genesee County, with Batavia as the county seat. The company sold parcels until 1846, when the company was dissolved. The phrase "doing a land office business" dates from this era.