134 A HISTORY OF AMERICA IN 100 MAPS
The map of the Oregon Trail on the previous page
was published immediately after the United States
annexed Texas, and just before it acquired California,
Oregon, and the Intermountain West. We often
consider this enormous growth in the mid-1840s as
an inevitable stage of American history, but it hinged
on a series of highly contested events. Just as maps
of the Oregon Trail stimulated the imagination of
migrants and expansionists, so too did this pocket
map show Americans a much larger West that would
come almost entirely under American control by 1848.
The question of Texas had long bedeviled
Americans. In 1821 Mexico achieved independence
from Spain, thereby inheriting a vast North American
empire that encompassed California, Texas, and
everything in between. Officials in Mexico City
struggled to control these distant territories against
raids by equestrian bands of Apache and Comanche
that roamed across what is now Texas and Oklahoma.
Hoping to fortify this northern frontier, Mexico
offered land to Americans in exchange for vague
promises to convert to Catholicism. By 1835, 35,000
Americans had migrated west into Texas, many of
them slaveholders intending to grow cotton. Mexico
responded by outlawing slavery in 1829 and closing
the border to Americans the following year. Both
strategies proved fruitless: Americans continued
to immigrate into Texas illegally, and the slave
population increased.
Relations between Americans and Mexicans
in Texas also deteriorated, the result of cultural
differences and the desire among many whites to
separate from Mexico. In 1836 a group of these
American settlers—and a few Mexican allies—
declared themselves an independent republic and
immediately sought annexation by the United States.
Washington demurred for fear of provoking a war
with Mexico, which refused to acknowledge Texas
as an independent state. Moreover, the admission
of Texas to the Union would immediately upset the
delicate balance between slave and free states in
Congress. Texas thus remained independent for the
next nine years. Then, in 1844, the Democrat James
Polk campaigned for the presidency on a platform
of national expansion. His victory signaled a political
A CONTINENTAL NATION
Samuel Augustus Mitchell, “A New Map
of Texas Oregon and California,” 1846
shift, and sitting President John Tyler immediately
proposed to annex Texas.
At the end of 1845 President Polk celebrated the
addition of Texas as “a bloodless achievement.”
He aimed to continue that momentum by pressing
Congress to negotiate a favorable boundary with
Great Britain in Oregon. Thousands of Americans
had already migrated to the Far West, well before it
was part of the country. Soon those settlers began to
demand federal protection, forcing the question of
whether the United States ought to annex Oregon as
it had Texas. Faced with their cries of “54° 40' or Fight,”
Polk advocated a boundary across the forty-ninth
parallel north, marked on the map in dark ink. The
British countered by proposing a border further south
on the Columbia River, along with a smaller American
province on the coast. The United States rejected the
offer, and ultimately won a national boundary on the
forty-ninth parallel.
Meanwhile, Mexico treated the American
annexation of Texas as a violation of national
sovereignty. Here Samuel Augustus Mitchell’s highly
popular pocket map claimed the Rio Grande as the
southern border of Texas, though Mexico insisted that
the Nueces River to the north was the proper boundary.
That dispute led to a war that engulfed California as
well, which in turn declared its own independence
from Mexico. Though the war was brief, it remains one
of the most divisive in American history, regarded by
many Northerners as a naked land grab on behalf of
slaveholders and expansionists. Others worried that
the nation’s belligerence and aggressive growth had
transformed it into a corrupt and overextended empire.
Mitchell’s map captures all of these geopolitical
shifts of the 1840s. It was particularly valuable to
Mormons, tens of thousands of whom were then
fleeing persecution in the Midwest. Just weeks after the
map was published, Brigham Young asked for copies
to aid the exodus of the Latter-Day Saints to Deseret,
later Utah. With information about travel distances
and geography, Mitchell’s map was a reliable,
inexpensive, and portable companion for Mormons
leaving the United States. Little did they realize that
their refuge in northern Mexico would soon become
American territory. The Treaty of Guadalupe Hidalgo
ended the war with Mexico in 1848, and granted all
of “Upper California,” depicted in pink, to the United
States. Within days, the discovery of gold in California
had sparked a frenzied worldwide migration to San
Francisco that is detailed on the next map.