On October 25, 1784, Frederick Haldimand, Captain General and Governor in Chief of what will become Canada, issues the Haldimand Proclamation. The conditions of the proclamation permit "the said Mohawk Nation, and such other of the Six Nation Indians" to settle on the banks of the Grand River (in present-day Ontario). More precisely, the territory is six miles (9.6 kilometers) on either side of the river beginning at Lake Erie and extending upwards to the head of the Grand River. Haldimand's term of office ends before he gives Brant legal title to the land.

Joseph Brant spends much of his time trying to resolve the Grand River land claim. On January 14, 1793, Lieutenant John Graves Simcoe issues the Simcoe Patent. This patent grants to the Six Nations 675,000 acres (223,163 hectares) of land along the Grand River. This parcel is 275,000 acres (111,289 hectares) less than what was stipulated in the Haldimand Proclamation.

By 1828, nearly two-thirds of the Grand River territory is sold, leased or occupied by squatters. By 1847, the Six Nations Reserve at Grand River is only 49,400 acres (19,992 hectares).

In July 1974, the Six Nations Land Claims Research Office is created. Its focus is to pursue the terms laid out in the Haldimand Proclamation of 1784.