Lesson 2: The Mexican American War

What is the Mexican-American War?

The Mexican War began on April 25th, 1846, and lasted until February 2nd, 1848. The main cause of the war was land, specifically over Texas. The United States wanted Texas and was able to annex it in 1845. However, Mexico still claimed Texas and refused to acknowledge it as a U.S. territory. Under the guise of Manifest Destiny, President James K. Polk sought to expand even more after annexing Texas and thus provoked Mexico into the war. In the end, the U.S. won through the signing of the Treaty of Guadalupe Hidalgo and gained lands now known as Nevada, Utah, New Mexico, and Arizona. 

"The Mexican-American War - Explained in 16 Minutes" 


Key Terms

Annexation: The act of adding a territory to an existing political unit, such as a country or state.

Sovereignty: The authority of a state to govern itself or another state; the concept of supreme power.

Cession: The formal giving up of rights, property, or territory by a state or country.

Manifest Destiny: The 19th-century doctrine that the expansion of the United States throughout the American continents was both justified and inevitable.

Expansionism: The policy of territorial or economic expansion, often pursued by a nation to increase its influence and power.

Tension: A state of mental or emotional strain; in this context, the growing conflict between different nations or groups.

Treaty: A formally concluded and ratified agreement between countries, typically ending a conflict or establishing terms of peace.

Revolt: An act of rebellion against authority or government, often involving armed conflict.

 

Lesson Activities

Activity 1: The Consequences of the War

Activity 2: Mexican-American War Debate

Activity 3: How the Treaty of Guadalupe Hidalgo Affects Me

    Activity 4: Perspective Creative Writing: Voices of the War

    Extra Resources and Materials

    Website/articles
    Interactive Online Exhibition - The Price of Freedom: Mexican War

    Primary Documents

    Treaty of Paris: This legal document is the first in U.S. history where the territory is annexed but does not become part of the United States. It does not grant citizenship to those territories but does treat them as a foreign possession. The 2nd clause, article 2 declares how Puerto Rico and Guam are given to the United States by the Spanish. 

    Treaty of Guadalupe Hidalgo: It declared peace between the U.S. and Mexico. The legal doctrine declared that Mexico must cede 55% of its territory. The treaty also extended U.S. citizenship to Mexicans living in the now U.S. territories unless they wanted to retain their Mexican citizenship. Rio Grande was also recognized as the boundary between the two countries.


    Companion Lesson

    Extranjeros and Expansion