In the struggle for the control of Oregon lands, Thurston was an ally of Jason Lee against John McLoughlin, the chief of the Hudson's Bay Company at Fort Vancouver who had helped thwart settlement in the territory. As Congressional delegate, Thurston authored the Donation Land Claim Act so as to give McLoughlin's HBC claim to the state legislature. Thurston and Lee made false statements about McLoughlin before the United States Supreme Court in an effort to publicly discredit him. The statements resulted in the denial of McLoughlin's land claims to his homestead in Oregon City.