Camp Dubois, near present day
Hartford,
Illinois, served as the winter camp for the
Lewis and Clark Expedition from
December 12,
1803, to
May 14,
1804. It was located on the east side of the
Mississippi River so that it was still in
United States territory. This was important because the transfer of the
Louisiana Purchase to
France from
Spain did not occur until
March 9,
1804, and then from France to the United States on
March 10,
1804. They returned again to the camp on their return journey on
September 23,
1806.
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