Because the Corps of Discovery was as much an instrument of empire as
it was a scientific journey, the Spanish and British were understandably
not pleased with the American presence. The expedition was viewed as
a threat to Spanish possessions in the west and for the British, it
meant serious competition for the fur trade and a network of Indian
alliances. Spain went so far as to send a military force to intercept
the Corps, but were unsuccessful in doing so. The British sought to
step up its presence on the Great Plains and particularly in the Pacific
Northwest, where American claims to the area had already been contested.
The part of North Dakota that was in the Hudson’s Bay drainage
system was signed over to the United States in 1818 when the 49th parallel
was the agreed-upon border. Later, in the 1840's period of “Manifest
Destiny”, the Lewis and Clark expedition proved to have been the
harbinger of later conflicts for land, trade, and wealth.
