Bellwork
• Why didn’t the United States Congress
support the annexation of Texas?
American History
Section 11, Unit 2
American Expansionism
Objectives
• What issues and events led to the war
between the U.S. and Mexico?
• What territories did the United states gain as a
result of the war?
• What was the impact of war on former
Mexican citizens?
• Describe how Polk was able to expand the
boundaries of the United States under his
presidency.
Oregon Country
• Long before the issues
concerning Texas
annexation (which we will
discuss again soon)
merchants had been
trading in the Far West–
as far back as 1790.
• After Mexican
independence in 1821,
trade increased with the
Mexican government as
they promoted trade with
the U.S.
Santa Fe Trail
• Trails, such as the Santa Fe Trail– a 700 mile
trail from Missouri to Santa Fe– opened the
East to new markets in the West.
• Such trade routes allowed U.S. merchants to
control much of the trade within the Mexican
borders.
Oregon Trail
• As trade spread, between 1811 and 1813, trappers
and mountain men in the Rockies blazed a new
route known as the Oregon Trail.
• The Oregon trail opened up new routes for farmers
and religious missionaries.
Oregon Trail
• Despite the benefits of the new trail, there
were issues:
1. Native American groups in the area blamed
missionaries for spreading disease in the region
that severely reduced Native population.
2. Native American attacks had occurred, although
rare.
3. The journey– considering the time- was
extremely rigorous and dangerous.
Expansion
• With all this new western land available,
expansionists, primarily southerners and
Democrats, hoped to add Texas, Oregon
Country, and northern Mexico to the United
states.
• As we will see, this war would have a long
term impact on the Mexican citizens left in the
U.S.
Texas Annexation
• Between 1836 and 1845, the question of Texas
annexation did not die.
• Many– convinced it was America’s destiny to
expand westward– believed the citizens of
Texas should be part of the Union.
• The issue was hotly debated in Congress.
Questions:
1. Why did they believe it was America’s “destiny” to
control these lands?
2. Why didn’t Congress want to allow Texas in at first?
Debate over annexation
• Supporters of Texas annexation argued that if
Texas was not admitted, Britain might gain
influence there.
– Britain had previously shown an interest in the
marketplace of an independent Texas.
• Opponents, however, argued that Texas
joining the union would increase the South’s
power in Congress and upset the balance of
slave and free states.
Debate of Annexation
• The issue of western
expansion became an
issue into the 1844
presidential campaigns.
• In these campaigns,
Whig party candidate
Henry Clay faced
against Democrat James
K. Polk.
Known as “Young Hickory”, James K. Polk
was the protégé of Andrew Jackson and
was actually endorsed by Jackson when he
ran for House Speaker and when he ran for
the 1844 Election.
Election of 1844
• Polk, a Tennessee
politician, called for the
annexation of Texas and
Oregon.
• Clay’s platform, however,
did not mention Texas at
all.
– Partly due to this, Polk
received 170 electoral
votes to Clay’s 105, but the
popular vote was much
closer– only a fivethousand difference.
James K. Polk
• Polk was an expansionist who, in 1844, was
successful at “negotiating” with Britain at
dividing Oregon country at the 49th parallel
(the modern Canadian boundary).
– In reality, Polk forced Britain’s hand by declaring
that all of Oregon to Alaska was the United States.
– Britain ultimately caved in and gave up the Oregon
territory.
Question: Do you think taking Oregon Country would be enough for
Polk? If not, what else would he want?
James K. Polk
• Polk’s call for Texas
annexation caused
tensions with Mexico.
• Mexico had warned that
annexing Texas would be
akin to declaring war
against them.
– Issues got so tense that, in
1845, when Congress was
deciding to annex Texas,
Mexico broke diplomatic
relations with the U.S.
Tensions rise
• Polk fueled the tensions by
demanding that it
recognize the Rio Grande as
Mexico’s northern border–
100 miles south of where
they originally had their
border.
• To back up his demand,
Polk ordered troops under
General Zachary Taylor to
move to the disputed
territory.
– Polk was well aware that
such as action would provoke
an armed clash with Mexican
troops.
Tensions rise
• After receiving information that Mexico was
willing to resume diplomatic relations, Polk
sent politician John Slidell to Mexico in 1845
to establish the Rio Grande as the border.
• When Mexican cities learned of Slidell’s
mission, they reaction furiously– the Mexican
government caved in to public pressure and
refused to negotiate with Slidell.
Tensions rise
• Following the refusal to speak to Slidell, Polk
ordered General Taylor to move deeper into
disputed area.
• Publicly, Polk made it seem as if he was
protecting American territory.
– In reality, however, he was hoping Mexico would
commit an act to justify a war.
Question: Why do you think Polk wanted a war?
Polk had hoped for a war to give him a chance
to finally expand American territory into the
West.
The Mexican War
• In 1846, Polk had finally heard the news he
had waited for: the Mexican troops crossed
the Rio Grande and attacked a U.S. patrol.
• Polk sent his war message to Congress:
“Mexico has invaded our territory and shed
American blood upon American soil.”
• On May 13, 1846, Congress declared war.
The Mexican War
• Some Americans,
primarily the Whigs and
northerners, criticized
the Mexican War and
called it “Mr. Polk’s
war”.
– One politician,
Congressman Abraham
Lincoln of Illinois
demanded that the
president show exactly
where the blood was
spilled. If it was on
American soil, he’d
support it. If not, he
argued the war was
unjustified.
The Mexican War
• Polk’s opponents also charged that the war
was aimed at trying to get more slave
territory.
• Abolitionists across the country– including
Henry David Thoreau and Frederick Douglass–
heavily criticized the war and, in some cases,
refused to pay taxes to support the war.
Question: Who might actually support the war?
The Mexican War
• While the opposition to
the war was great, most
Americans– especially
southerners and those
in the west– wanted
Mexican lands for
agriculture.
• Many began to enlist in
the military to help
support the war effort.
The Mexican War
• While Taylor pushed into
northern Mexico to seize
lands, others moved into
New Mexico and California.
• In 1846, led by General
Stephen Kearny, a U.S.
military force took Santa Fe
and won control of New
Mexico.
• After that, Kearny marched
into California where U.S.
settlers revolted against
Mexican rule.
The Mexican War
• In what became known as the Bear Flag Revolt,
Californians raised a flag bearing a grizzly bear on it
and declared California an independent republic
from Mexico.
• The American military also aided these rebels in
fighting back against Mexico.
The Mexican War
• As the war continued, American troops
captured San Pasqual near San Diego, and
after several battles, U.S. troops under Kearny
and Commodore Robert Stockton defeated
Mexican troops near Los Angeles.
• The victory near Los Angeles sealed the defeat
for Mexico in California.
The Mexican War
• In the final campaign of the
war, the U.S. engaged in a
bold plan to take Mexico
City.
• Led by General Winfield
Scott, around 10,000 U.S.
troops captured the
fortified castle of Veracruz
on the Gulf of Mexico.
• Soon after, General Scott
maneuvered into position
to attack the heart of the
Mexican nation.
The Mexican War
• The Mexicans battled valiantly against the
incoming U.S. troops.
• Despite the resistance, however, U.S. troops
succeeded in reaching the National Palace,
which President Santa Anna had abandoned.
• Ultimately, the U.S. troops assaulted and
captured the capital September 14, 1847.
The Treaty of Guadalupe Hidalgo
• By the end of September, U.S. forces held
California and New Mexico; General Taylor’s
forces occupied much of Northern Mexico
while General Scott controlled Mexico City.
• In February, 1848, the Treaty of Guadalupe
Hidalgo ended the war on terms dictated by
the U.S.
Treaty of Guadalupe Hidalgo
• By the terms of the treaty, Mexico gave up all
claims to Texas and what was known as the
Mexican Cession: California, Nevada, Utah and
parts of Arizona, Colorado, and New Mexico.
• In return, the U.S. agreed to pay Mexico $15
million and take over part of the payment of
damages held against Mexico by Americans.
Question: While we won the war, why might it have been a good
idea to still pay the Mexican government for the land?
Treaty of Guadalupe Hidalgo
• As well, the treaty also
promised full citizenship
to Mexican citizens who
are affected by the
Mexican Cession and
that Americans would
respect their religious
beliefs and property
rights.
Mexican Cession
Look carefully, what didn’t Americans get?
Gadsden Purchase
• In 1853, U.S. diplomat James Gadsden
negotiated a deal with Mexico to buy a strip of
land in present day Arizona and New Mexico
for $10 million.
• With the Gadsden Purchase, the U.S. acquired
all of Mexico’s territory north of the Rio
Grande river.
Gadsden Purchase
What is shaded
in yellow was
the Gadsden
Purchase.
Territories–
including those
we haven’t
talked about
yet
Mexican Americans
• The Treaty of Guadalupe Hidalgo and the war
resulted in about 80,000 Spanish-speaking
people becoming part of the U.S. instantly.
• However, many of these new citizens left,
feeling like “foreigners in their own land”.
Mexican Americans
• For many Mexican-Americans– many of those
who had already been in contact with U.S.
citizens– the adjustments were fairly easy.
• Despite the guarantees in 1848, however,
many Mexican Americans lost their land.
– Many couldn’t afford the costly legal battles to
defend their lands or lacked “accepted”
documentation for their lands.
– Many previous land owners took low-paying jobs
in the mines or railroads.
Mexican Americans
• Many Americans looked down on the culture
of the region, which blended Spanish,
Mexican, and Indian culture together.
• The resulting atmosphere and discrimination
against many Mexican Americans sparked
rebellions in the southwest.
Mexican Americans
• One such rebellion was lead
by Juan Nepomuceno
Cortina, a Tejano rancher
and politician.
• He led a rebellion in 1859
after shooting and
wounding a Texas marshal
who used excessive force on
another Tejano.
– Cortina fled south of the Rio
Grande but continued to
spark small rebellions in the
area well into the 1870’s.
Mexican Americans
• In response to such rebellions (and later issues
ensuing), Americans in the region began to
intimidate Mexican American communities
through harassment, beatings, and even
murders.
• The bitter issues that were raised during the
Mexican War took a long time to subside.
New Lands
• With new lands available to the Americans,
people slowly began to stream into the West,
seeking fortune and fame that awaited them
in the new states– primarily California.
Review Objectives
• What issues and events led to the war
between the U.S. and Mexico?
• What territories did the United states gain as a
result of the war?
• What was the impact of war on former
Mexican citizens?
• Describe how Polk was able to expand the
boundaries of the United States under his
presidency.
Questions?
• If you have any questions, please ask now.
Next lesson
• In the next lesson, we will begin discussing the
prelude to the Civil War.
Review
1. Briefly explain what led up to the Mexican War.
2. How were Mexican Americans supposed to be treated
under the Treaty of Guadalupe Hidalgo? What
happened in reality?
3. What modern states did the United States gain in the
Mexican Cession?
4. Why did some Americans criticize the Mexican War?
5. Why did some Americans support Texas annexation?
Why did others oppose it?
6. How did Anglo-Americans react to Mexican Americans
rebelling against them?
7. Some politicians referred to the Mexican War as “Mr.
Polk’s War”. Do you think they are a fair point when
they referred to it as such? Why or why not?