Investigative Question

What were the consequences of the Mexican–American War?

In addition to learning about the political, economic, and ideological justifications for western expansion, students study the northward movement of settlers from Mexico into the Southwest, with emphasis on the location of Mexican settlements, their cultural traditions, attitudes toward slavery, the land-grant system, and the economy that was established. Students need this background before they can analyze the events that followed the arrival of westward-moving settlers from the East into Mexican territories. Students explore the settlement of Americans in northern Mexico and the actions to establish the Republic of Texas. Teachers provide special attention to the causes and consequences of the United States’ war with Mexico by considering the question What were the consequences of the Mexican-American War? To answer this question, students study early territorial settlements, the political ambitions of James K. Polk and other proslavery politicians, and the war’s aftermath on the lives of the Mexican families who first lived in the region. Students also study the Treaty of Guadalupe Hidalgo and the California Constitution of 1849 and the effects of both documents on the lives of Mexicans living within the new United States borders.

In fighting the Mexican–American War, the United States demanded that Mexico relinquish its northern lands. The ceded territory included present-day California, Arizona, New Mexico, and parts of Utah, Colorado, and Nevada — the sites of numerous Mexican towns and Native villages that had been occupied for millennia. The war began as a result of a territorial dispute following the Texas Revolt. In 1824 the recently independent Republic of Mexico wanted to populate its northern lands with settlers. The republic created the Colonization Law, which allowed US citizens to settle on Mexican lands in Texas as long as they became Mexican citizens and respected Mexican law. The deal was very popular; many settlers rushed into Texas, especially from the southern states, and occupied large ranches. Many brought slaves. When Mexico abolished slavery in 1829, however, the Texans became weary of Mexican law. The Texans became increasingly defiant of Mexican law and in 1835 declared their independence. Although Mexico was unable to defeat the rebellion, it claimed that it had never relinquished control of the territory. But in 1845 the US government annexed Texas as the 28th state, which ultimately led to the Mexican–American War. The war had profound consequences for the lives of the people living in this region, as well as on US political debates regarding slave and free territory. In the coming decades the United States initiated industrial and agricultural development, as well as settlement, on an unprecedented scale throughout the region. The result was widespread environmental change, from the conversion of the plains to wheat farms, forests to lumber, and mountains to mining quarries. In short, there were significant social, political, environmental, and economic consequences of the war. This source set begins with the Treaty of Guadalupe Hidalgo, with a special focus on Article VIII. Students read the promises outlined in the treaty and can use this as a base when assessing the experience of the Mexican Americans and the indigenous peoples now living in the United States under the terms of this treaty. Significantly, the United States did not count Native Americans as US citizens until 1924, thereby negating any rights they may have received as a result of the Treaty of Guadalupe Hidalgo. The Disturnell Treaty map (1847) is also included to help students understand the enormity of the land Mexico was required to cede to the United States. This map shows how Mexico had organized its northern territories, the extent of the territory lost in the Texas Revolt, existing Mexican towns, and various Native-controlled regions. Large swaths of territory were never settled by Spain or Mexico, meaning that indigenous populations lived in relative peace. Indian Territory is also shown, which was created in 1830 under Andrew Jackson’s Indian Removal Act. The map is also useful as a springboard for a discussion of slavery in the West and how the newly acquired lands would be divided over the issue. This map must be analyzed along with various new policies that affected the former Mexican citizens. Native Californians were not recognized as Mexican and so were not protected by the Treaty of Guadalupe Hidalgo. Their lands were taken and they were brutally exterminated. The third source is the Act for the Government and Protection of Indians, which allowed the kidnapping of indigenous children. The act reveals the precarious situation for Native Californians after US annexation. Two additional maps in this set give students the opportunity to consider changing rules regarding property rights from the Mexican to the US era in California. These rules, along with the common feeling of racial superiority and entitlement to the western lands among white Americans, all had a significant impact on the lives of those who held Mexican ranchos and further hindered the opportunities available to California’s indigenous peoples. Sources 4 through 6 reflect this. The discussion of the dispossession of Mexican land should be coupled with the creation of laws that sought to disempower the Mexican population, who had legal rights and property rights under the Treaty of Guadalupe Hidalgo. Source 7 will spur discussion of Mexican resistance to racial and legal discrimination. Meanwhile, American settlers, as well as people from around the world, settled in the West and converted its natural resources into marketable goods. Source 8 includes the example of Marysville, a town that grew rapidly in response to the Gold Rush. Other industries followed on the heels of the Gold Rush, as the hotels and other commercial establishments in Source 8 indicate. Source 9 reveals the growing tensions between Anglo and Chinese populations. Finally, this source set concludes by considering the political implications of the Mexican–American War on the slave-state vs. free-state debate that was racking the United States. Source 10 reveals the issue of the Compromise of 1850, which made California a free state. Students examine the Archy Lee case, which deals with the Fugitive Slave Act. Students will consider how the incorporation of the once-Mexican lands into the United States had significance not only for the people in this region but also for the political makeup of the entire United States.
Literacy Support (Source 1: Treaty of Guadalupe Hidalgo, Article VIII) Teacher Background: Article VIII can be difficult for students to parse because of challenging vocabulary (including everyday words like said and remove used in more academic senses), sentences with multiple noun and verb phrases to organize, and heavy use of pronouns and ellipses that can make it hard to keep track of who or what is being referred to at any given moment. This literacy strategy focuses student attention on the vocabulary needed to understand the passage and also models a visual technique for organizing sentences and pieces of sentences. Directions: 1. Provide context. Briefly provide context on how the Treaty of Guadalupe Hidalgo came about and the scope of the entire treaty. Then, explain that Article VIII is a particularly important part of the treaty to understand because it outlines the promises the United States made to Mexicans who owned property in the newly acquired US territory. Explain that a solid understanding of these original promises is necessary so the class can assess the experiences of Mexican Americans living under the treaty. If this is the first time you are engaging in sentence deconstruction activities in your class, provide context for students about the value of sentence deconstruction as a close reading strategy for difficult texts. Explain that the purpose of sentence deconstruction is to slow down and understand how the pieces of the text fit together. Note that professional historians also read documents many times over, closely and carefully, so this is a form of learning to read as a historian does. 2. Interpret and discuss text. Provide students a copy of Article VIII (Student Handout 1). Give them a chance to look it over quickly, and then discuss why parts of it can be difficult to read (lots of pronouns standing in for nouns, sometimes important words are omitted or implied, etc.). Turn to Student Handout 2. Explain to students that the text is the same but that it has been laid out visually to better illustrate the relationship between different parts of the text. (For example, the first chunk of text sets up two choices, which then serve as the basis for the next two chunks of text.) Explain to students that some blanks were left for them to fill in from the original text, so they will have to immerse themselves closely in the original text (as historians do). Tell them also that these particular blanks represent important vocabulary and language usages that are important for understanding the document; this should help them begin to notice context and figure out the words. After students fill in the blanks, have them work in pairs or small groups to complete the first two sections of Student Handout 3 of the handout, inferring the meaning of the vocabulary words and summarizing the different chunks of the text. Debrief these answers as a whole class so everyone develops a solid foundation of the meaning of the text. At the bottom of Student Handout 3, have students compose a response about their reaction to the promises of Article VIII. Allow some time for students to process their ideas in discussions with their peers before or after writing. These initial ideas can be revisited throughout the unit as students learn more about the experiences of Mexican Americans living under the treaty. 3. Extend the learning. To reinforce one of the literacy strategies modeled in this lesson — breaking apart and visually organizing sentences or pieces of sentences — you might choose another small bit of difficult text from the unit in which there are multiple noun or verb phrases per sentence. Write these sentence parts on slips of paper and ask students to help lay them out in a way that visually makes the relationship between parts clearer. Alternatively, if students are ready, they could work in small groups to decide how to break apart a passage themselves and write it on large pieces of paper. To provide vocabulary reinforcement and writing practice, you might ask students to write sentences or a paragraph in which they use some of the focal vocabulary words studied in Article VIII, especially those that will be the highest frequency words for students moving forward, like acquire and retain. Handouts 8.8 The Social and Economic Impact of the US-Mx War in CA Student Handout 8.8 The Social and Economic Impact of the US-Mx War in CA Teacher Key
  • The Library of Congress. The Library of Congress’ Primary Source Analysis Tool supports an inquiry model of instruction by asking students to first observe, then reflect, then question. Their customizable tool includes specific prompts for student interrogation of books and other printed materials, maps, oral recordings, photographs and paintings, and many other types of primary sources.
  • The National Archives and Records Administration (NARA). NARA has developed a vast collection of document analysis worksheets, ready for classroom use. Their website offers teachers a wide collection of customizable tools – appropriate for working with photographs, maps, written documents, and more. NARA has also customized their tools to meet the needs of young learners, and intermediate or secondary students.