While Jefferson was concerned about developing the new United States, markets in Europe were demanding furs for their clothes and hats.
The Hudson's Bay company had been in this trade for a century in competition with the French, but now the British owned the whole of northern North America.
The Americans were worried about this trade monopoly, and so successful ex-British traders like John Jacob Astor, began to set up rival networks. Both Canadians and Americans used mountainmen and Native American to gather pelts.
