Texas Independence and
the Mexican Revolution
Tensions between Mexico and the US
Mexican government encouraged US
settlement in Texas
Prevent border violations
Protection from Natives
Mexico gave massive land grants to
empresarios
Bring in settlers and sell land
Pledged to obey Mexican laws and observe the
Roman Catholic faith
Tensions between Mexico and the US
Until 1830s, most Anglos willing to live by
these rules
As population surged, Mexico rethought
immigration policies
Tensions over social issues
1829: Mexico had freed slaves, insisted Texans
do the same
1830: Mexico closed borders, created heavy
import tax on goods from U.S.
Texas Fights for Independence!
Mexico didn’t have
enough troops to
enforce border closure
1833: Santa Anna
suspended Mexican
constitution
Rebellion erupts …
the Texas Revolution
is on!
Fight at the Alamo!
 Santa Anna determined to
force Texas to obey Mexican
law
 Anglo forces moved to Alamo;
if they could hold the Alamo,
they could stop Santa Anna
 Feb 23-March 6, 1836: Santa
Anna attacked Alamo
Siege ended when Mexican
troops scaled the walls
Independence!
March 2, 1836: Texas declared independence,
arguing Mexico had violated fundamental
rights
March 16, 1836: Texans ratified constitution
based on the US. Constitution
“Remember the Alamo!”
Six weeks after Alamo, Houston and 900
men surprised Mexican soldiers at Battle
of San Jacinto
Texans killed 630 Mexicans in 15 minutes,
captured Santa Anna
Santa Anna freed only after he signed
Treaty of Velasco granting independence
to Texas
Analyzing Independence
Read the packet of documents (A-D)
and fill out the graphic organizer.
Make sure to answer the question at
the bottom since this will lead into a
class discussion!
Analyzing Independence
1. Why did Texans declare independence?
2. Were these honorable men, fighting for freedom, or
greedy slaveholders?
 What evidence from the documents supports your
opinion?
 Which of these pieces of evidence do you find
more/less trustworthy? Why?
 Why do historians still debate this question?
3. Once Texas declares and wins its independence,
why would Mexico object to American annexation
of Texas?
The Republic of Texas
 1836: San Houston elected president of
the Republic of Texas
 Most Texans hoped U.S. would annex
Southerners pro annexation since
slavery used in Texas
Northerners against for same reason
Texas Annexation
1844: Southern expansionist James A.
Polk elected President
March 1845: Congress approved Texas
annexation
Dec 1845: Texas officially 28th state
Mexico cut off all diplomatic ties with the
U.S.
Causes of MexicanAmerican War
1. Manifest Destiny
2. Annexation of Texas by U.S.
3. Dispute over the boundary of
Texas
Boundary Dispute
Texas and U.S. claim that the Rio
Grande marks the southern border
of Texas
Mexican government argues that
the border is the Nueces River
Rio Grande boundary
Nueces River boundary
War on the Horizon: “Mr. Polk’s War”
“In the White House now was James Polk, a Democrat,
an expansionist, who, on the night of his inauguration,
confided to his Secretary of the Navy that one of his
main objectives was the acquisition of California. His
order to General Taylor to move troops to the Rio
Grande was a challenge to the Mexicans. It was not at all
clear that the Rio Grande was the southern boundary of
Texas, although Texas had forced the defeated Mexican
general Santa Anna to say so when he was a prisoner.
The traditional border between Texas and Mexico had
been the Nueces River, about 150 miles to the north,
and both Mexico and the United States had recognized
that as the border. However, Polk, encouraging the
Texans to accept annexation, had assured them he
would uphold their claims to the Rio Grande.
Ordering troops to the Rio Grande, into territory
inhabited by Mexicans, was clearly a provocation.
Taylor had once denounced the idea of the annexation
of Texas. But now that he had his marching orders, his
attitude seemed to change.”
Don’t
mess with
Texas
James K. Polk
Prelude to War
Read the selection from The PBS
documentary “Manifest Destiny and the
Mexican American War.” Respond to these
two questions:
1. What political, economic, and social
pressures promoted American
expansion?
2. Why was it nearly impossible for Mexico
to protect its northern territories like
Texas and California?
Politics and War
 Polk believed war with Mexico
would win the U.S. more territory
 In Mexico, Santa Anna replaced
by General Jose Herrera
 Nov 1845: Polk sent John Slidell
to Mexico to purchase California
and New Mexico and extend the
official Texas border to Rio Grande
 Herrera refused to meet with
Slidell
John Slidell
Politics and War
Polk figured any form of
Mexican aggression would
unify country
Ordered General Zachary
Taylor to blockade the Rio
Grande
Mexican government saw
this as violation of Mexican
border
Boundary Violations!
March 1846: Taylor made camp at
the Rio Grande in disputed territory
April 1846: Mexican commander
insisted U.S. troops leave, Taylor
refused
Mexican forces crossed the Rio
Grande, attacked U.S. soldiers
11 Americans killed
Declaring War…
May 11, 1846: Polk asked Congress for
declaration of war
“Mexico has shed American blood upon the
American soil”
Two days later Congress declared war on
Mexico
Support for the War
1. Southerners supported war – new
slave territories
2. Greater national pride
3. Spread democratic values
Opposition to the War
1. Whig Party thought the conflict was
unjustified
2. Abolitionists feared new slave
territories
1848: Illinois Congressman Abraham
Lincoln wrote the “Spot Resolutions”
asking Polk to show the spot where
American blood had been shed on
American soil
Gaining New Mexico
1846: Polk orders troops to march
from Kansas to Santa Fe, NM (all 800
miles!)
Troops met by New Mexicans who
wanted to join the US
New Mexico was won without a shot
being fired!
Gaining California
 1845: American settlers, angry that Mexico had
turned down U.S. offer to buy CA, seized town
of Sonoma
Raised flag with image of grizzly bear
Declared independence from Mexico, named
themselves the “Bear Flag Republic”
 U.S. troops arrived and Mexican troops gave
way
The War Moves South
 Under the command of Ulysses S. Grant
and Robert E. Lee, numerous American
victories
 Mexican troops tried, but were generally
unsuccessful
 Polk and Santa Anna: if Polk helped him
return to power, Santa Anna would sign a
peace accord with U.S.
The War Ends…
Mexico
Lost 50,000 men
Lost nearly half its land
General hatred of the United States
grows
United States
Lost 13,000 men – 2,000 to battle,
11,000 to disease
Enlarged territory by 1/3
The Treaty of Guadalupe Hidalgo
Forced on Mexican government
U.S. gained:
1. California, Nevada, and Utah
2. Most of Arizona and New Mexico
3. Parts of Colorado and Wyoming
Texas southern boundary would be Rio
Grande
U.S. agreed to pay $15 million to
Mexico and pay Mexican debts to U.S.
citizens
Gadsden Purchase
1853: President Franklin Pierce
authorized $10 million payment to
Mexico for one last piece of territory
Last piece of territory in what makes up the
modern day continental U.S.