The Mexican-American War: Arguments for and against Going to War

by Tim Bailey

Unit Overview

Over the course of three lessons the students will analyze two primary source documents that represent two different points of view on the Mexican-American War. The first document is a speech delivered by then President James K. Polk justifying America’s war with Mexico and asking the United States Congress for a declaration of war. The second document is a speech by Congressman Joshua Giddings during the debate in the House of Representatives that questions the President’s motives for and handling of the coming conflict. Students will closely read and analyze these speeches with the purpose of not only understanding the literal meaning but also inferring the more subtle contexts within these documents. Students will use textual evidence to draw their conclusions and present arguments as directed in each lesson culminating in a mock debate oral presentation.

Lesson 1

Objective

In this lesson the students will carefully read a primary source document, a speech delivered by President James K. Polk asking the United States Congress for a Declaration of War against the country of Mexico. The students will analyze the document and identify the arguments that are being made in favor of declaring war.

Introduction

The border between Texas and Mexico had been a subject of much debate ever since Texas won its independence from Mexico in 1836. Even after Texas was annexed by the United States in 1845, the question of whether its southern border was the Rio Grande River or the Nueces River, about 150 miles to the north, was greatly contested. This was the situation when James K. Polk became president. Polk believed that the United States had a “Manifest Destiny” to reach from the Atlantic Ocean to the shores of the Pacific. To help fulfill this destiny Polk sent a US representative to the Mexican government in order to make an offer to buy California and parts of New Mexico as well as to settle the disputed territory in Texas. In exchange for this land he offered $25–$30 million and an additional $3 million in debt relief owed to American citizens by Mexico. The Mexican government refused to meet with the representative. Consequently, Polk ordered the US Army to move into the disputed territory. Fighting broke out on April 25, 1846, when a Mexican force killed sixteen American soldiers in the disputed territory south of the Nueces River.

Materials

Procedures:

At the teacher’s discretion you may choose to have the students do the lessons individually, as partners, or in small groups of no more than three or four students.

  1. Discuss the information in the introduction. You may have the students take notes on the information.
  2. Hand out President Polk’s speech to Congress.
  3. The teacher then “share reads” this document with the students. This is done by having the students follow along silently while the teacher begins reading aloud. The teacher models prosody, inflection, and punctuation. The teacher then asks the class to join in with the reading after a few sentences while the teacher continues to read along with the students, still serving as the model for the class. This technique will support struggling readers as well as English Language Learners (ELL).
  4. Students will look at the document and then determine which are the most important words or phrases in that text and copy those words into the box on the right. After they have determined what is most important they will summarize the text in their own words.
  5. Students can brainstorm as partners or small groups but must finish their own organizer in order to complete the assignment.
  6. Class discussion. What is the central argument being made in Polk’s speech? Have groups or individual students share their summaries and compare with other groups. Remember to emphasize that they are to first use the author’s own words to determine what is important in the text and then to summarize what they understand it to mean.

Lesson 2

Objective

In this lesson the students will carefully read a primary source document, a speech delivered by Congressman Joshua Giddings during a debate in the House of Representatives just prior to the vote on President James K. Polk’s request that the United States Congress declare war against the country of Mexico. The students will analyze the document and identify the arguments that are being made against declaring war.   

Introduction

For a number of representatives in Congress, especially those from the northern states, a decision in favor of going to war with Mexico had little to do with national pride or fair trade practices and everything to do with American slavery and imperialistic expansion. Although these voices were in the minority they were vocal in their opposition to the President. Among those opposed to the war with Mexico was the newly elected congressman Abraham Lincoln. Author Henry David Thoreau refused to pay taxes that would support the war and was subsequently jailed, where he wrote his essay Civil Disobedience. Yet despite the arguments raised by northern congressmen, war was declared only hours after Giddings gave his speech.

Materials

Procedures

At the teacher’s discretion you may choose to have the students do the lessons individually, as partners, or in small groups of no more than three or four students.

  1. Discuss the information in the introduction. You may have the students take notes on the information.
  2. Hand out Congressman Joshua Giddings’s speech to Congress.
  3. The teacher then “share reads” this document with the students. This is done by having the students follow along silently while the teacher begins reading aloud. The teacher models prosody, inflection, and punctuation. The teacher then asks the class to join in with the reading after a few sentences while the teacher continues to read along with the students, still serving as the model for the class. This technique will support struggling readers as well as English Language Learners (ELL).
  4. Students will look at the document and then determine which are the most important words or phrases in that text and copy those words into the box on the right. After they have determined what is most important they will summarize the text in their own words.
  5. Students can brainstorm as partners or small groups but must finish their own organizer in order to complete the assignment.
  6. Class discussion. What is the central argument being made in Giddings’s speech? Have groups or individual students share their summaries and compare with other groups. Remember to emphasize that they are to first use the author’s own words to determine what is important in the text and then to summarize what they understand it to mean.

Lesson 3

Objective

In this lesson the students will demonstrate their understanding of the documents presented over the past two lessons. They will be participating in a mock debate in which they will be role-playing proponents of and opponents to the war with Mexico and debating questions concerning the wisdom and consequences of this conflict.      

Introduction:

War was declared against Mexico on May 13, 1846. The war lasted a little over a year and a half from 1846 to 1848 and finally ended with the capture of Mexico City by American forces and the signing of the Treaty of Guadalupe-Hidalgo. This treaty gave the United States possession of vast amounts of land including the future states of California, Nevada, Utah, and parts of Arizona, New Mexico, Oklahoma, Colorado, and Wyoming. Mexico also agreed to drop its claims on Texas. In return the Mexican government received $15 million and the United States assumed the debts that Mexico owed to American citizens.

Materials:

Procedures

Students should be organized into groups of 3-5three to four students. All of the students should have copies of the listed materials.

  1. Do not discuss the information in the introduction until the conclusion of the lesson.
  2. Tell the students that they are going to have a mock debate based on the arguments given in the two speeches that they have studied over the past two lessons. They need to choose one person in their group to be a debate moderator and an even number of students divided into those for and those against the war.
  3. Inform the students that they will be writing the script for a debate based on the issues raised in the primary documents that they have been studying. This script is to be written as a team effort and everyone in the group will have a copy of the final script. This will not be an actual debate but more like a short reader’s-theater piece.
  4. The teacher will provide a question that all groups must address during their debate. However, the students should add another two to four relevant questions as long as the answers can be taken directly from the primary source material.
  5. It is important that the students portraying those who are in favor of going to war and those who are opposed to going to war use the actual text from the documents to make their arguments.
  6. Give the students the following question to be asked by the moderator and addressed by both sides (remember to back up arguments with the actual document text):

What do you believe is your opponents’ weakest argument as to declaring war or not declaring war on Mexico? (Make sure to base your answer on evidence from the text.)

  1. Students can then construct two to four questions of their own choosing to be answered by either side with the opportunity for rebuttal.
  2. Remind the students that everyone in the group needs to work on the script, not just one side or the other, and that the responses need to be taken directly from what the authors of the documents said.
  3. One student in the group acts as the debate moderator and asks the scripted questions that were written by the group. Students will present their debates to the rest of the class while role-playing both sides of the argument:to declare war or not to declare war.
  4. Class discussion: After all of the debate presentations are concluded discuss the best arguments made by the groups and the best text-based evidence used.

Extension:

After two years of fighting American forces defeated the Mexican army and captured the county’s capital of Mexico City. The Mexican-American war ended on February 2, 1848 with the signing of the Treaty of Guadalupe Hidalgo. By signing this treaty the United States agreed to pay Mexico $15 million while Mexico gave up 55 percent of its territory, including parts of present-day Arizona, California, New Mexico, Texas, Colorado, Nevada, and Utah, to the United States.

Materials

Procedure

Students should examine both the Treaty of Guadalupe Hidalgo as well as the map that was used in negotiating the Treaty. Use the following questions to focus their analysis.

Critical Thinking Questions:

  1. Which Article of the treaty is responsible for defining the new national boundaries between the two countries?
  2. According to Article VIII what happens to Mexican citizens that live in territories now claimed by the United States?
  3. According to Article XII how long will it take the United States to pay Mexico for the land the U.S. has just acquired?
  4. According to Articles XXI and XXII what are some of the “rules” if war breaks out again between Mexico and the United States?
  5. Using the “Map of the United States of Mexico" and a contemporary map of the United States and Mexico determine how much of its territory Mexico was losing as well as how much larger the United States was becoming.

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