Texas and the Mexican-American War

Event Notes

Santa Anna


Charismatic but ruthless general Antonio Lopéz de Santa Anna seizes power in Mexico City. He favors a centralized, authoritarian government which angers people as most people are in favor of autonomy.


1835 - 1836

Texans rebel against Mexican rule, they seize Mexican garrisons at Goliad and San Antonio. This leads to Texas declaring independence and becoming known as the Lone Star Republic.

Texas in 1835


Texas is home to 30,000 American settlers named Anglo-Texans.


March, 1836

Santa Anna attacks a small Texas garrison at the Alamo. He slaughters the Texans here and at Goliad. The slaughtered become martyrs to Texas independence.

Battle of San Jacinto

April, 1836

Sam Houston tricks Santa Anna and eventually captures Santa Anna and 730 Mexicans at the Battle of San Jacinto. Santa Anna is forced into signing a treaty recognizing Texas independence. The Mexican government does not accept the treaty as it grants Texas lots of land.

1844 Election


James K. Polk is voted in as President because of his promises to obtain the Oregon territory and Texas. He does not keep his promise to obtain all of Oregon which angers Democrats.


December 1845

Congress narrowly votes to annex Texas, which enters the Union as a slave state. The border dispute between Texas and Mexico is reignited.

War Begins

May, 1846 - May 13, 1846

American troops led by General Zachary Taylor clash with a Mexican patrol killing eleven. This allows Polk to declare war on Mexico, which Congress approves on May 13.


June, 1846

Polk compromises with the British and agrees to split the Oregon territory at the 49th parallel of latitude. Northern democrats feel betrayed by this action of compromising.

Conquering of New Mexico

June, 1846 - August, 1846

General Stephen W. Kearny conquers New Mexico. The US Navy helps settlers seize control of California . Kearny and Frémont join forces to bring all of California under American control.


September, 1846

Taylor leads army deeper into northern Mexico, seizing the city of Monterrey.

Battle of Buena Vista

February, 1847

Santa Anna tries to retake Monterrey, but Taylor's small army defeats the Mexicans in this bloody battle.


March, 1847

The navy carries an american army to Veracruz where General Scott seizes the port. Scott then marches 200 miles to Mexico City where he faces great resistance at Chapultepec (a fortress above Mexico City) from defenders including six children.

War Ends

September, 1847

General Scott captures Mexico City effectively ending the war in a thorough American victory.