U.S. History
It’s All Mine!
Manifest Destiny Becomes a Reality
1. The United States had been expanding since Great Britain first recognized its independence in
1783. After the Louisiana Purchase, the western boundary of the United States was the Rocky
Mountains. Many Americans hoped that this trend in westward expansion would continue. They
wanted the U.S. to stretch from sea to shining sea (meaning from the Atlantic Ocean in the east
to the Pacific Ocean in the west). John O’Sullivan, an American journalist, wrote, “Our manifest
destiny [is] to overspread and possess the whole of the continent in which Providence {God} has
given us for the development of the great experiment of liberty and….self government.”
O’Sullivan used the word “manifest” to mean clear or obvious. The word “destiny” means events
are sure to happen. Therefore the term “m
manifest destiny” suggested that the United States was
destined to expand to the Pacific Ocean. Americans hoped that one day manifest destiny would
become a reality.
2. There was one major problem for those who supported manifest destiny; other nations had
already claimed the land bordering the Pacific Ocean. Mexico occupied the southwestern portion
of the land. The Mexican Territory included much of the present-day states of California, Nevada,
Utah, Arizona and New Mexico. The northwest portion of the land was called the Oregon
Territory. It included much of the present-day states of Oregon, Washington, Idaho, Montana
and southwest Canada. The Oregon Territory was owned by both the United States and Great
Britain. Additionally, many Native Americans laid claim to this land as well. If manifest destiny
were to become a reality, the United States would need to acquire this land.
3. The United States had a relatively easy time acquiring the Oregon Territory. By the 1840s,
thousands of Americans had moved into the territory, which the United States had shared with
Great Britain since 1818. Both Great Britain and the United States wanted to control the entire
territory, but neither country wanted to go to war for the third time in 70 years. Rather than
fight for full ownership of the territory, U.S. President James Polk struck a deal with Great Britain
called the Oregon Treaty of 1846. The treaty split the territory in two at the 49th parallel (49oN).
Through the treaty, the United States was given the southern half of the territory (present-day
Washington, Oregon, Idaho) and Great Britain retained controlled the northern part of the
territory (present-day Canada).
4. President Polk had a good reason for wanting to avoid war with Great Britain. By 1846, he had
much bigger troubles brewing with Mexico over Texas. In 1845, Congress admitted Texas as a
slave state, in spite of Northern objections to the spread of slavery. However, Mexico still claimed
Texas as its own. Mexico viewed the United States’ annexation of Texas as an act of war. Mexico
believed that the United States had no right to claim Texas for its own. Mexico was willing to go
to war over the ownership of Texas. President Polk, wanting to avoid war, sent a representative to
Mexico to strike a peaceful settlement. The United States offered Mexico $25 million for Texas,
California and New Mexico. Mexico refused the offer.
5. Immediately after Mexico refused to accept the American’s offer to purchase the land, Polk
stationed American Army troops at the Rio Grande (the southern border of Texas). Viewing this
as an act of war, Mexico moved its troops to the other side of the Rio Grande. On April 25th,
1846, a Mexican cavalry unit crossed the river and attacked the U.S. troops, killing 16 American
soldiers. This act marked the beginning of the Mexican-American War.
6. In May, 1846, the United States army, led by General Zachary Taylor, invaded Mexico. He hoped
that the Mexicans would be easily defeated and that the war would end quickly. The war with
Mexico proved to be much more difficult than the United States had anticipated. The Mexican
army was much larger than the U.S. army, but the U.S. troops were being led by well-trained
officers. On February 22, 1847, 4,800 U.S. troops battled against 15,000 Mexican troops. After
two days, the Mexican Army retreated. The American troops pressed onward and in September of
1847, Mexico City, the country’s capital, fell.
7. In February of 1848, the United States and Mexico signed the Treaty of Guadalupe Hidalgo. In
this treaty, Mexico recognized that Texas was part of the United States. Mexico also ceded a vast
piece of land that included California, Nevada, Utah, Arizona, and parts of New Mexico, Colorado
and Wyoming. All together, Mexico lost about one half of its land to the United States as a
result of the Treaty of Guadalupe Hidalgo. In 1853, the United States purchased one more piece
of land from Mexico (the southern parts of Arizona and New Mexico) for $10 million in what
became known as the Gadsden Purchase. The United States had finally realized its Manifest
Destiny and stretched from “sea to shining sea”.
Map outlining the progress of the United States towards its “manifest destiny”
Name:
Date:
Core:
U.S. History
Reflections on Manifest Destiny
(…and text Structure )
Directions: Use the It’s All Mine: Manifest Destiny Becomes a Reality handout to answer the following
questions.
1. Which of the following best describes the structure of the paragraph 2?
a) cause/effect
c) main idea/supporting details
b) compare/contrast
d) sequence of events
Identify evidence from the text that helped you to identify the text structure of this paragraph? ______
______________________________________________________________________________________
______________________________________________________________________________________
2. Which of the following best describes the structure of the paragraph 3?
a) cause/effect
c) main idea/supporting details
b) compare/contrast
d) sequence of events
Identify evidence from the text that helped you to identify the text structure of this paragraph? ______
______________________________________________________________________________________
______________________________________________________________________________________
3. Which of the following best describes the structure of the entire text?
a) cause/effect
c) main idea/supporting details
b) compare/contrast
d) sequence of events
Identify evidence from the text that helped you to identify the text structure of this paragraph? ______
______________________________________________________________________________________
______________________________________________________________________________________
4. Read the sentences below:
Mexico viewed the United States’ annexation of Texas as an act of war. Mexico believed that
the United States had no right to claim Texas for its own. Mexico was willing to go to war
over the ownership of Texas
Which of the following probably means the same thing as the word “aannexation”?
a. purchase
b. joining together
c. destruction
d. renaming
5. Read the sentence below:
Mexico also ceded a vast piece of land that included California, Nevada, Utah, Arizona, and
parts of New Mexico, Colorado and Wyoming. All together, Mexico lost about one half of
its land to the United States as a result of the Treaty of Guadalupe Hidalgo.
Which of the following probably means the same thing as the word “cceded”?
a. To surrender
b. To take over
c. To violently struggle
d. To sell