Westward Expansion & The Mexican-American War

The Missouri Compromise, Manifest Destiny, Texas Independence, and The Mexican-American War

How westward expansion began divide the nation between North and South

The Missouri Compromise: Quick Review

The Missouri Compromise of 1820. It a). Allowed Missouri to enter the Union as a slave state and Maine as a free state. and b.) The southern border of Missouri, 36’30, would serve as a slavery line across the country.  To the south, slavery was permitted.  To the north, it was free territory.

Multiple Choice

The Missouri Compromise created a slavery line across the western part of the United States. If a new state was created in the west TO THE NORTH OF THE LINE, would it be a FREE STATE or a SLAVE STATE?

• free state

• slave state

Open Ended

What do you think this painting is about?

Manifest Destiny

New York Post editor John O’Sullivan wrote in 1845, “It is our manifest destiny to overspread and to possess the whole of the continent which Providence has given us.”  

Add to Notes: Manifest Destiny was the belief that the United States should expand west to the Pacific Ocean.

Manifest Destiny: the belief that the United States should expand west to the Pacific Ocean

Example:

What is it like?

Manifest Destiny- John L. O'Sullivan, July 1845
It is time for opposition to the Annexation of Texas to cease…Texas is now ours…Let their reception into the “family” be frank, kindly, and cheerful…

Other nations have undertaken…hostile interference against us…hampering our power, limiting our greatness and checking the fulfillment of our manifest destiny to overspread the continent allotted by Providence (God) for the free development of our yearly multiplying millions.

California will, probably, next fall away from (Mexico)...Imbecile and distracted, Mexico never can exert any real governmental authority over such a country…The Anglo-Saxon foot is already on California’s borders…armed with the plough and the rifle, and marking its trail with schools and colleges, courts and representative halls, mills and meeting houses…All this will happen in the natural flow of events…

​Document A

Multiple Choice

What does "Manifest Destiny" mean?

• Destiny likes festivals, man.

• the belief that the U.S. should expand to the Pacific Ocean

• something about destiny and flying....and....

• the belief that the U.S. should jump in the Pacific Ocean

Westward Expansion

In addition to the La.Purchase, there were two major events which contribute to the expansion: Texas Independence and the Mexican-American War.

Texas Independence and the U.S.-Mexican War

An Interactive Timeline of Events that Led to War

As we move through this timeline, consider, WAS THE UNITED STATES RIGHT TO GO TO WAR WITH MEXICO?

Tomorrow, you will write a short essay answering this question. Today, we'll present the facts, evidence, primary sources and maps to explain the story of when the US and Mexico engaged in war.

Multiple Choice

In 1820, which country secured its independence from Spain?

• the United States

• Mexico

• Canada

• Haiti

1820

Mexico has secured its independence from Spain and is an independent republic. Its territory spanned from the Yucatan peninsula, and as far north as Oregon.

Multiple Choice

With few settlers living in the province of Texas, Mexico will offer cheap land to Americans in order to build up settlement in this area.

• True

• False

Multiple Choice

As the abolition movement (the movement to END SLAVERY) grew worldwide, Mexico will choose to….

• strenghthen its protection of slavery

• abolish slavery

• do nothing

1829

The last slaves are freed in Mexico. 

The first black president of Mexico gets elected- Vicente Guerrero.

Guerrero is later assassinated.

Multiple Choice

After Mexico abolished slavery, slaves in Texas will be freed.

• True

• False

1835

Mexico’s new constitution  centralizes power and made slavery illegal in all Mexican territories, including Texas.  

However, Texans do not free their slaves.

American settlers decided they wanted independence from Mexico.

Charles Sumner, "Objections to the Mexican American War" 1847

Mexico, on achieving her independence of the Spanish Crown…decreed the abolition of human slavery within her dominions, embracing the province of Texas…

At this period, citizens of the United States had already begun to move into Texas…The idea was…that this extensive province ought to become a part of the United States…

A current of emigration soon followed from the United States.  Slaveholders crossed the Sabine river into Texas with their slaves, in defiance of the Mexican ordinance of freedom.  Restless spirits, discontented at home…joined them…The work of rebellion sped.  Our newspapers excited the lust of territorial robbery in the public mind…Certainly Mexico might justly charge our citizens with disgraceful robbery, while, in seeking extension of slavery, our own citizens denied the great truths of American freedom…

Multiple Choice

In 1836, the Texas battle for Independence begins. At the Alamo, in San Antonio, the Texas win their independence.

• True! Remember the Alamo!

• False! Remember the Alamo!

VI. 1836- Texas Independence (1836)

The Texas Revolution starts.  The Texans lose badly in San Antonio at The Alamo.

Later, Texans secure a victory at San Jacinto.  Mexican general, Santa Anna, is captured and signs a peace treaty, securing Texas Independence.
Texas breaks away from Mexico.

Multiple Choice

Did Mexican General Santa Anna have the authority to surrender Texas with a peace treaty?

• Yes, generals are usually the ones having to surrender.

• No, only the Mexican government had that authority.

1836

The U.S. recognizes the peace treaty of Velasco. 

Later, the Mexican government says Santa Anna had no authority to sign the treaty, and that Texas is still part of Mexican territory.

Multiple Choice

Texas was an independent country for almost nine years.

• TRUE. The Lone Star Republic.

• FALSE. No state in U.S. history was ever its own independent country.

1836-1845:  The Texas Republic

For close to nine years, Texas was an independent country, although not recognized by Mexico.  

Texas declares slavery legal.

Texas applies to become a U.S. state but is it told "NO" because Anti-Slavery congressmen feared multiple slave states being carved from Texas territory.

Multiple Choice

Which president campaigned on the idea of adding Texas (independent, sorta), California and New Mexico (both part of Mexico)?

• THOMAS JEFFERSON

• JAMES K. POLK

• ABRAHAM LINCOLN

1844

James K. Polk is elected President of the U.S. 
VII. During his campaign, future President Polk promises to annex (add) Texas to the United States.

He’d also wanted to add California and New Mexico.

1845

In one of his last acts as President, John Tyler (outgoing president) signs the Congressional resolution to annex Texas.

VIII. Texas becomes a slave state, after much controversy. Polk takes office.

Polk talks of expanding the U.S. and “extending the dominions of peace” in his inaugural speech.

Multiple Choice

President Polk will send troops to the Texas-Mexico border.

• True

• False

1845

March-Mexican ambassador Juan Almonte returns to Mexico in response to Texas annexation.

April-Mexican President Jose de Herrera sends Santa Anna into exile.

June-Texas accepts the U.S. annexation (it becomes a state)

July-Polk sends orders to General Zachary Taylor to organize army along the Texas-Mexico border in Corpus Christi, TX.  John O’Sullivan uses the term “Manifest Destiny.”

Multiple Choice

President Polk tried to buy California from Mexico.

• TRUE, but Mexico said “no” (en Espanol)

• FALSE, Polk will not "try" to "buy" California.

November 1845

President Polk sent John Slidell to Mexico with instructions to try to buy New Mexico and California.  

President Herrera refuses to meet with Slidell.

Multiple Choice

President Polk wants to go to war with Mexico to get California.

• True

• False

• Maybe

December 1845

President Polk starts to build a case that the U.S. may be forced to go to war with Mexico.

Multiple Choice

American troops will move into disputed territory claimed by Mexico and the U.S.

• True

• False

January 1846

General Mariano Paredes Y Arrillaga then made himself president of Mexico. 

Paredes also refused to meet with Slidell. He he did not want to sell northern Mexico.

President Polk sends General Taylor to the Rio Grande, and Commodore Conner is ordered to the port of Veracruz.

American troops move into the disputed territory, claimed by both the U.S. and Mexico.

Multiple Choice

What will occur next between Mexico and the U.S. in 1846?

• The United States will move South of the Rio Grande and start a war.

• Mexico forces move into the disputed territory to remove American troops.

• Mexico declares war on the United States.

• The United States declares war on Mexico.

April 1846

General Mariano Arista orders Mexican troops to cross north of the Rio Grande.  They surround the U.S. scouting party and several Americans are killed.

General Taylor sends Polk a letter declaring that “hostilities have commenced.”

IX. In May 1846, Polk receives the letter and encourages Congress to declare war on Mexico.

American Blood shed on American soil

Polk says in his message to Congress (1846) that troops have been moved into an area to "meet a threatened invasion of Texas by Mexican forces." It was "plainly our duty to extend our protection over her citizens and soil." "Mexico has passed the boundary of the United States, has invaded our territory, and shed American blood upon the American soil."

"The US Invasion...An outright attack on Mexico"

From Jesus Velasco-Marquez, Instituto Tecnologico Autonomo de Mexico "A Mexican Viewpoint on the War with the US," 2006 DOCUMENT C

From Mexico’s point of view , the annexation of Texas to the United States was inadmissible for both legal and security reasons.  Thus, when the Mexican government learned of the treaty signed between Texas and the United States in April 1844, it …would consider such an act “a declaration of war.”...

In early 1846, on Polk’s orders, the troops commanded by General Zachary Taylor arrived at the Rio Grande, across from the city of Matamoros, thus occupying the territory in dispute and increasing the possibilities of a confrontation…In the eyes of the Mexican government, the mobilization of the US army was an outright attack on Mexico…As a consequence, the Mexican government reaffirmed the instruction to protect the border, meaning the territory located between the Rio Grande and the Nueces River--an order which led to the battles of Palo Alto and the Resaca de la Palma…

One article in the daily El Tiempo… states:  “The American government acted like a bandit who came upon a traveler.”.

Multiple Choice

What the heck is happening in California?

• Nothing, California is a part of....oh wait, it's part of Mexico at this time.

• Gold

• Settlers from the United States are revolting...again

June 1846

American settlers in California arrest Mexican politician Mariano Vallejo as part of what comes to be known as the “Bear Flag Revolt.”  

The Americans write a constitution and declared California an independent republic.

California Americans declare allegiance to the U.S. in July.

Multiple Choice

Which cities will see fighting in the Mexican-American war?

• Los Angeles, just like a Hollywood movie

• Mexico City...the U.S. invaded Mexico

• Veracruz

• All of the above

September 1846

The War begins with American troops invading California and New Mexico by September.

American forces capture Monterrey, Saltillo, & Los Angeles by the end of the year.

American Victories at Buena Vista, Veracruz, and Cerro Gordo lead to the invasion and eventual capture of Mexico City in 1847.

Multiple Choice

How will the war end?

• After capturing Mexico City, the U.S. is able to force a treaty.

• With the advantage, the U.S. offers to buy California, again for $15 million.

• Using the war as a tool, the U.S. takes all of northern Mexico, including California.

• All of these choices are correct.

1848

Gold is discovered in California.
X. United States victory brings new territory in what is now called the Mexican Cession.

The Treaty of Guadalupe-Hidalgo: On February 2, the U.S. negotiates a peace agreement and will pay Mexico $15 million for California and New Mexico.  

The Texas border will be the Rio Grande River.

Mexicans in these territories will be able to become U.S. citizens.

Did President Polk provoke a war to take land from Mexico?

"It is our manifest destiny to overspread the continent...California will, probably, next fall away from Mexico." -John O'Sullivan

Was it actually the U.S. that invaded Mexico?

"In the eyes of the Mexican government, the mobilization of U.S. troops into the disputed territory was an outright attack on Mexico." -Dr. Jesus Velasco-Marques, Instituto Technologico Autonomo de Mexico

Was the Mexican War an effort by Southern politicians to expand slavery westward?

"Mexico might justly charge our citizens with disgraceful robbery, while in seeking an extension of slavery.." -Senator Charles Sumner, Massachusetts

Was the Mexican-American war justified? Was the U.S. right to go to war with Mexico in 1846?

Go to Canvas to access the Mexican War Mini-Essay doc