1. Mexican-American War Ch. 14, Sect. 2
Essential Question: What were the causes and effects of the Mexican-American War?
Key Terms: cede, abolitionist
Key People: James K. Polk, John Slidell, Mariano Paredes, Zachary Taylor, Winfield Scott, Santa Anna, Henry Clay, James Pearce

2. Causes of the War
Mexico never recognized the Republic of Texas and considered the USA’s annexation of Texas an insult.
Mexico refused to accept the Rio Grande as the official boundary between Texas and Mexico. Instead, they insisted the Nueces River separated the country and state.

3. Causes of the War
Mexico was angered by the USA’s efforts to expand trade by trying to acquire the Pacific port of San Francisco.
The USA offered Mexico 30 million in return for:
Mexico accepting the Rio Grande as the Mexico-Texas boundary, and …
Mexico ceding California and the western half of New Mexico to the USA.

4. Causes of the War
December 1845: President Polk sent John Slidell to Mexico to negotiate the boundary dispute and offer to buy California; but diplomatic relations broke down.
March 1846: President Polk ordered General Zachary Taylor to move his troops across the Nueces River to the Rio Grande.
John Slidell

5. REASONS FOR THE MEXICAN WAR
OCTOBER 1845
POLK SENDS TAYLOR
TO NUECES
BORDER
DISPUTE: RIO GRANDE OR NUECES?

6. REASONS FOR THE MEXICAN WAR
DECEMBER 1845
SLIDELL SENT TO
MEXICO – MEXICO
REFUSES TO SEE HIM
- INSULTS USA

7. War Declared
April 1846: American and Mexican forces clash at the Rio Grande in the disputed territory.
U.S. President Polk declared Mexico had shed American blood on American soil.
Mexican President Parades could have claimed vice versa.
May 13, 1846: U.S. Congress declared war on Mexico.

8. REASONS FOR THE MEXICAN WAR
JANUARY 1846
POLK
ORDERS
TAYLOR
TO RIO
GRANDE
April 1846
MEXICANS
ATTACK!

9. Taylor and Polk’s Justification for War
MAY 1846
Taylor and Polk’s Justification for War
POLK ASKS CONGRESS FOR
DECLARATION OF WAR

10. Congressman Abraham Lincoln
War Debated
Most Southerners favored the war—more territory meant more slave states.
Northerners opposed it for same reason.
Abolitionists questioned the American motives to possibly expand slavery.
Illinois Congressman Abraham Lincoln’s Spot Resolution: “Show me the spot where American blood was shed!”
Congressman Abraham Lincoln

11. Discussion Question #1
Was the United States justified in sending troops to the Rio Grande? Why or why not?

12. SPOT RESOLUTION SOME OPPOSE MR. POLK’S WAR MAY 1846 WHERE WASB O L I T N S
WHERE WAS
THE SPOT?

13. U.S. MILITARY FAR SUPERIOR
AMERICAN STRATEGY
STRATEGY
U.S. MILITARY FAR SUPERIOR
OCCUPY TEXAS
AND NORTHERN
MEXICO
2. TAKE NEW
MEXICO AND
CALIFORNIA
3. MARCH ON
MEXICO CITY

14. General Zachary Taylor
United States Victory
The U.S. forces were better led and equipped.
General Zachary Taylor captured Monterrey and later defeated Santa Anna at Buena Vista.
General Winfield Scott landed at Vera Cruz and captured Mexico City in September 1847.
First marine landing in U.S. History
General Zachary Taylor

15. WINFIELD SCOTT SENT SOUTH TO MEXICO LANDS IN VERA CRUZ
ON TO MEXICO CITY
WINFIELD
SCOTT
SENT SOUTH TO MEXICO
LANDS IN
VERA CRUZ
HE PUSHES TOWARD
MEXICO CITY

16. Albert Sidney Johnston
Texans in the War
More than 5,000 Texans, including the Texas Rangers who served as scouts, fought with the U.S.
Notables include Edward Burleson, Albert Sidney Johnston, Mirabeau Lamar, and J. Pinckney Henderson.
Sadly, anti-Mexican feelings caused some Texans to abuse Mexican civilians.
Edward Burleson
Albert Sidney Johnston

17. Discussion Question #2
Some Texans soldiers mistreated Mexican civilians in the Mexican-American War. Does war justify such actions, or might such behavior be considered a crime?

18. Treaty of Guadalupe Hidalgo
Feb. 2, 1848: The Peace Treaty at Guadalupe Hidalgo signed to end war.
Rio Grande became boundary.
Mexico surrendered area called the Mexican Cession. The U.S. paid $15 million for this land.
Mexicans living in this area would have the rights of U.S. citizenship.

19. Discussion Questions #3 and 4
How do you think felt about the United States after the Mexican Cession? Why?
How would you have felt as a Mexican Citizen in areas that became part of the United States?

20. Mexico lost about half of its land. U.S. pays Mexico $15 million.
TREATY OF GUADALUPE HIDALGO
WAR HEROES
Taylor and Scott
Mexican Cession will one day be the states of:
California, Nevada, Utah, and parts of Colorado, Arizona, New Mexico & Wyoming.
Mexico lost about half of its land.
U.S. pays Mexico $15 million.

21. The New Mexico Boundary Dispute
The question of whether Santa Fe would become part of Texas became a political issue in the U.S.
The people of Santa Fe preferred to be a separate territory or state rather than be a part of Texas.

22. The Pearce Act (of The Compromise of 1850)
Former presidential candidate Henry Clay and Maryland congressman James A. Pearce helped write the Pearce Act, as part of the Compromise of 1850.
Texas gave up lands that it claimed in present-day New Mexico (which includes Santa Fe) and received $10 million to pay its war debt.
U.S. Congressman James A Pearce

23. The Compromise of 1850, con’t
TEXAS AND THE COMPROMISE OF 1850
The Compromise of 1850, con’t
Provisions of the Compromise of 1850
California became a state
Utah and New Mexico became territories
Slave trade was ended in Washington DC
Fugitive Slave Law was put into place
“Texas Question”: Texas received 10 million dollars to give up disputed territory to north and west
Getting the money helped Texas get out of debt
Texas and New Mexico Act of September 9, 1850: created Texas’ present day borders

24. The Gadsden Purchase
In 1853, the U.S. paid Mexico an additional $10 million for the Gadsden Purchase, a strip of land along the edge of present-day Arizona and New Mexico.

25. The United States Achieves
Manifest Destiny