ter could not compete. The posts of the North West Company
on the Red River of the North became the resort for many of the western
tribes.[6]

The diverting of the trade of these natives, who would naturally have
come down the Missouri where American traders could meet them and be
benefited, was noticed by President Jefferson, who, on January 18, 1803,
wrote to Congress: "It is, however, understood, that the country on that
river is inhabited by numerous tribes, who furnish great supplies of
furs and peltry to the trade of another nation, carried on in a high
latitude, through an infinite number of portages and lakes, shut up by
ice through a long season." In this same message was included a
recommendation that a small expedition be sent up to confer with the
tribes with respect to the admission of American traders.[7]

But the purchase of Louisiana altered matters. It was not only a matter
of trade, but one of sovereignty. A double movement was initiated: one
to ascend the Mississippi under Zebulon M. Pike, and the other the
Missouri under Captain Meriwether Lewis and Lieutenant William Clark.
The reports of these two expeditions indicate how firm a grip the
English traders had upon the Indians of the upper Northwest.

The expedition of Lewis and Clark ascended the Missouri and passed over
the mountains to the Columbia River which was followed to the coast. The
first winter, from late in October, 1804, to early in April, 1805, was
spent in a fort which was constructed in the village of the Mandans,
near the location of the present city of Mandan in North Dakota. Here
was abundant opportunity to investigate the fur trade. Nor had they long
to wait. On the 27th of November, seven British traders arrived from the
North West Company's post on the Assiniboine River to barter with the
river tribes. The next day, in council with the Mandan chiefs, the
Americans warned the Indians not to receive medals or flags from the
foreigners if they wished to be friends with the "Great American
Father". A day later this warning was communicated to the traders
themselves who promised to refrain from any such acts.[8] How well they
kept their promises later events showed. The Lewis and Clark expedition
was only a passing pageant; for by the time of the War of 1812, the only
American traders who ventured to do business on the upper waters were
practically driven off by the foreign companies.[9]

The report of Zebulon M. Pike indicates th