A NATION REALIZED 113President Thomas Jefferson came into office with
an agrarian vision for his country; it required more
land to accommodate a nation of farmers. He also
inherited a belief that North America offered a
passage to India—with all its attendant commercial
rewards. As seen in earlier chapters, this hope
stretched back to the fifteenth century. These
two assumptions help to explain the president’s
enthusiasm for the Louisiana Purchase and his desire
to understand the geography of the Far West.
In large part Jefferson’s interest in a Northwest
Passage was driven by geopolitics. By the time he
became president, Spain had established control of
the Southwest and had built presidios up the Pacific
coast to San Francisco. Russian traders were actively
extending their networks further up the coast,
while British explorers continued their search for a
transcontinental portage from Hudson Bay to the
Pacific. Finally, the French, under Napoleon, flirted
with the hope of rekindling their interior empire
of trade along the Mississippi River. In 1800 North
America was alive with imperial competition.
Spain continued to claim much of the continent
west of the Mississippi River, and became
increasingly wary of American encroachment after
the Revolution. Late in 1802, Spanish authorities
abruptly closed the port of New Orleans to American
trade, which gravely threatened farming in the Ohio
Valley. Almost simultaneously, Spain was negotiating
a secret treaty to turn over the Louisiana Territory
to France. Jefferson was aware of this development,
and sought to negotiate with the French to reopen
access to New Orleans. To his great surprise the
French foreign minister was instructed to offer all of
Louisiana to the Americans for $15 million, mostly
through the forgiveness of debts incurred during
the French Revolution. In April 1803 the deal was
complete, and on Independence Day Jefferson
announced the Louisiana Purchase to the public.
BEFORE LEWIS AND CLARK
Samuel Lewis, “Louisiana,” in Aaron
Arrowsmith, A New and Elegant General
Atlas, 1804
Before the land transfer was finalized, Jefferson
sent a secret message to Congress requesting
support for an expedition to the Pacific to be
undertaken by his personal secretary, Meriwether
Lewis. Once authorized, the president instructed
Lewis to “explore the Missouri river, & such principal
stream of it” in order to discover “the most direct
& practicable water communication across this
continent, for the purposes of commerce.” Jefferson
was keenly aware of the multiple imperial interests
at play in the Far West, and hoped that improved
geographical knowledge of the region would
enable the Americans to leverage their position with
Europeans as well as native tribes.
Just what did Americans know about the Far
Northwest before Meriwether Lewis and William
Clark conducted their expedition? Here is the first
map of the Louisiana Territory after it was transferred
to American control, engraved by Samuel Lewis and
published in Aaron Arrowsmith’s A New and Elegant
General Atlas. Lewis took a broad view of Louisiana
in order to situate it within the geography of North
America. By deemphasizing national and imperial
boundaries, he drew attention to the topography and
river systems of the West.
Lewis based his map on one drawn by Antoine
Pierre Soulard in 1795. The Spanish governor of
Louisiana in St. Louis instructed Soulard to survey the
interior in order to gather geographical intelligence
about the Mississippi and Missouri river basins.
Soulard’s map included a few errors that were
replicated on Lewis’ 1803 map here, and it was those
errors which led Jefferson to believe that there was a
viable water route to the Pacific. The most striking of
these is the nearly uninterrupted chain of relatively
low mountains from Canada down through New
Mexico. This suggested that the “Stoney Mountains”
were narrow and easily traversed, which in turn fueled
Jefferson’s hope of a transcontinental passage. The
map also suggests that the headwaters of the Missouri
River were extremely close to those of the rivers flowing
west to the Pacific Ocean. This vastly underestimated
the course and reach of the Missouri, as well as the size
of the mountains. But the errors on the map show us
contemporary views of the continent, and by extension
Jefferson’s motives for the expedition.