The Mexican-American War began as the United States increasingly embraced the idea of Manifest Destiny and sought to expand its territory westward. President James K. Polk provoked Mexico into war by sending troops into disputed land along the Texas border. The U.S. then rapidly gained victories over Mexico, conquering northern Mexico. In 1848, the Treaty of Guadalupe Hidalgo ended the war, forcing Mexico to cede much of the modern-day American Southwest and California to the United States.

1. CHAPTER 11:
Expanding West
Section 3:
The Mexican –American War

2. Manifest Destiny

3. Manifest Destiny

4. #8 #9 #10
Martin William John
Van Buren Henry Tyler
“Martin Van Ruin” Harrison “His Accidency”
Died in 32 Days

5. #11
James
Polk

6. Manifest Destiny
 Most Americans believe in
manifest destiny
 But should slavery spread
west?
 James K. Polk is elected
President

7. Acquiring Oregon
 Britain and U.S. both claim
Oregon Territory

8. Acquiring Oregon

Americans
say “54 –
40 or
fight!”
 But 49 th
parallel is
agreed
upon
avoiding

9. Manifest Destiny

10. War Begins
 Texas agrees to become
part of the U.S.
 Polk wants California

11. War Begins
• He orders
General
Zachary
Taylor into
the disputed
area south of
Texas

12. War Begins
• Mexicans
attack Taylor
• U.S.
declares war
on Mexico

13. “Mexico has passed the boundary of the
United States, has invaded our territory, and
shed American blood upon American soil….
The two nations are now at war.”
James K. Polk

14. War Begins
 U.S. wins
early victories
at:
• Palo Alto
• Monterrey
• Buena Vista

16. Battle of Palo Alto

17. Battle of Monterrey

18. Battle of Buena Vista

19. The Bear Flag Revolt
 American settlers in
California revolt against
Mexico
 U.S. sees opportunity and
occupies California

21. The War Ends
 Polk replaces Taylor with
General Winfield Scott

23. The War Ends
• He wins
the Battle of
Veracruz
• Conquers
Mexico City
 Mexico
surrenders

24. Santa Anna’s
Artificial Leg

25. Treaties
 1848 – Treaty
of Guadalupe
Hidalgo ends
the war
 Also called
the Mexican
Cession
• Mexico
forced to give
up land

26. Mexican Cession

27. Treaties
 1853
–
Gadsde
n
Purcha
se
comple
tes
U.S.
Mexica