devised this expedition, had dwelt longingly on the prospect of crossing
the continent from the headwaters of the Missouri to the headwaters of
the then newly-discovered Columbia. The route thus explored was more
difficult than that which was later travelled by the first emigrants
across the continent to California. That route lies up the Platte River,
through what is known as the South Pass of the Rocky Mountains, by Great
Salt Lake and down the valley of the Humboldt into California, crossing
the Sierra Nevada at any one of several points leading into the valley
of the Sacramento. The route, which was opened by the gold-seekers, was
followed by the first railroads built across the continent. The route
that lay so firmly in Jefferson's mind, and which was followed up with
incredible hardships by the Lewis and Clark expedition, has since been
traversed by two railroads, built after the first transcontinental
rails were laid. If Jefferson had desired to find the shortest and most
feasible route across the continent, he would have pointed to the South
Pass and Utah basin trails. But these would have led the explorers into
California, then and long afterwards a Spanish possession. The entire
line finally traced over the Great Divide lay within the territory of
the United States.

But it must be remembered that while the expedition was being organized,
the vast Territory of Louisiana was as yet a French possession. Before
the party were brought together and their supplies collected,
the territory passed under the jurisdiction of the United States.
Nevertheless, that jurisdiction was not immediately acknowledged by
the officials who, up to that time, had been the representatives of the
French and Spanish governments. Part of the territory was transferred
from Spain to France and then from France to the United States. It was
intended that the exploring party should pass the winter of 1803-4 in
St. Louis, then a mere village which had been commonly known as Pain