In the 1860s, prospectors from Montana territory began moving across the border into now what is now Southern Alberta, seeking gold and silver. Many supplemented their prospecting by trading liquor for hides and buffalo robes. Soon reports came back to Fort Benton, Montana of the profits available in British America. Before long, forts were built to capitalize on the buffalo robe trade in Blackfoot territory. The first of these, Fort Hamilton, later christened Fort Whoop-Up, was the largest and most notorious

An American law passed in 1832 made it illegal to sell liquor to Indians, but was seldom enforced in Montana territory. With the establishment of a territorial government, the law began to be enforced, constraining traders operating in the US. In the fall of 1869, John J. Healy and his partner, Alfred B. Hamilton obtained a permit from American authorities to cross the Blackfeet Reservation.This permit had the effect of opening trade in British North America.

The permit stipulated that they were not to undertake any trade including alcohol on the Blackfeet Reservation. Once across the border, they were no longer subject to American law. Once more, Western Canada, at this time, had no effective form of law enforcement. Healy and Hamilton and about thirty men with six wagons of supplies arrived at the junction of the St. Mary’s and Belly River, a favourite winter camping area of Blood and Peigan.

Here construction of Fort Hamilton and trade with the Blackfeet Confederacy began. The trading was enormously lucrative. By the time, Healy and Hamilton returned to Fort Benton six months later, buffalo robes and furs worth almost $50,000 had been collected. Word of their success reached other traders and soon the robe trade in Southern Alberta was in full swing. Healy and Hamilton returned in the company of former Hudson’s Bay company employee and carpenter, William S. Gladstone and rebuilt Fort Hamilton.