1. Mexican-American War Ch. 15, Sect. 3
Essential Question: What were the causes and effects of the Mexican-American War?

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 Mexico refused to speak to him.
March 1846: President Polk ordered General Zachary Taylor to move his troops across the Nueces River to the Rio Grande.

5. REASONS FOR THE MEXICAN WAR
Let’s summarize!
What exactly was Mexico disputing?

6. REASONS FOR THE MEXICAN WAR
Let’s summarize!
Why did President Polk order General Taylor to move his troops across the Nueces River?

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. What was President Polk’s justification for war?
MAY 1846
Let’s summarize!
What was President Polk’s justification for war?

9. 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.
Congressman Abraham Lincoln

10. #showwhatyouknow
Do you think the United States justified in sending troops to the Rio Grande? Why or why not?

11. Strategy: 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

12. General Zachary Taylor
American Strategy
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

13. 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.

14. The Pearce Plan (of The Compromise of 1850)
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.

15. The Pearce Plan (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

16. 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

17. 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.
This was done so the U.S. could build a transcontinental railroad to the Pacific.

18. The United States Achieves
Manifest Destiny