What do you see?
MANIFEST DESTINY, THE OREGON
TRAIL, AND THE MEXICAN
AMERICAN WAR
Manifest Destiny

Manifest Destiny was the belief
that it was the destiny of the U.S.
to expand its territory over the
whole of North America – all land
between the Atlantic and Pacific
Oceans
Westward Ho!

Many Americans traveled through the Great
Plains to the land between the Rocky
Mountains and Pacific Ocean
 Why?
 Good
farmland
 Opportunity to start new
 “Make something of yourself”
Oregon Country
Present Northwest corner of the US and
part of Canada
 Fertile soil, plentiful rainfall, mild
temperatures
 Attracted farmers and trappers
 US, Britain, Spain and Russia all claimed
Oregon

Oregon Trail
2,000 miles long
 50,000 people traveled from 1840-1860
 Inspired by reports about fertile land
 Travelers met in Independence, Missouri
every May, and hoped to arrive in the
Oregon territory by October
 Dangerous journey – weather, disease,
geographic challenges

The Oregon Trail Clip
https://www.youtube.com/w
atch?v=CHps2SecuDk
Conflict with Mexico

Mexico became independent in 1821. The
Spanish governor of Texas gave some land to
American settlers if they promised to:
 Become
Mexican citizens
 Obey Mexican laws
 Become Catholics

Thousands of Americans flooded into Texas
 Many
did not feel any loyalty to Mexico, and
refused to follow their laws.

Mexican troops were sent to enforce laws.
US Territory Before Mexican
American War
Mexico’s New Leader

Texans did not like Santa Anna,
Mexico’s new leader
Military dictator
The Republic of Texas
Texans revolted against the Mexican
government, and in 1836, Texans
declared their independence from
Mexico and created the Republic of
Texas.
 Santa Anna, the president of Mexico
responded with force. His troops laid
siege to the Alamo, a mission in San
Antonio.

The Alamo
Defenders of the Alamo held out for
12 days under heavy cannon fire.
 All of the defenders were killed in
battle or executed afterward.

Texas Wins its Independence
Sam Houston led a small army in a
surprise attack against Santa Anna’s
army the following April. Texans
shouted “Remember the Alamo!”
 Within 18 minutes, the Texans had
captured Santa Anna.
 They forced him to sign a treaty
recognizing Texan independence.

Texas Becomes a State
Sam Houston became president of the
new Republic of Texas, and he hoped
the U.S. would annex Texas.
 Southerners supported annexation of
Texas as a slave state.
 Northerners opposed this, but still
hoped for western expansion.

Texas Becomes a State
For years after Texas won its
independence, the annexation of
Texas remained an unsettled question.
 It became a major issue in the
presidential election of 1844.
 James Polk beat Henry Clay in the
election, and shortly before he took
office, Texas was admitted as a state.

Tensions Rise

The annexation of Texas increased
tensions with Mexico – Mexico had
never formally recognized Texan
independence.
The Mexican American War
President Polk knew that the
Mexican government needed cash,
so he offered money to settle the
border dispute between Mexico
and Texas. Polk also offered to
buy California and New Mexico.
 Mexico refused the offers.

The Mexican American War




Polk hoped to provoke a Mexican attack on U.S.
troops, and sent General Zachary Taylor and his
troops to disputed land.
Mexico saw this as an act of war and ambushed
an American patrol.
Polk asked Congress for a declaration of war. He
claimed that Mexico had forced this war by
shedding “American blood upon American soil.”
The war began in 1846.
The Mexican American War
Polk sent General Taylor with 3,500
troops who defeated Mexico at Palo
Alto.
 Gen. Scott then led troops to take
Mexico City.
 With Mexico’s capital in U.S. hands,
the United States had won the war.

The Mexican American War Ends

The Treaty of Guadalupe Hidalgo ended the
Mexican American War in 1848.
 US got more than 500,000 sq. miles of
territory (CA, NV, UT, AZ, NM, WY, and
CO)
 Mexico dropped claims on Texas land at
Rio Grande River.
 President Polk paid Mexico $18 million for
the land

https://www.brainpop.com/socialstudies/ushistory/me
xicanamericanwar/
Manifest Destiny is Achieved
In the Gadsden Purchase of 1853, the
U.S. paid Mexico $10 million for a
narrow strip of present-day Arizona
and New Mexico.
 Manifest Destiny had been achieved.
 https://www.youtube.com/watch?v=
gn2FzuPyFlY
