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The U.S. At WarThe-US-At-War

  • Subject: U.S. History
  • |
  • Grade(s): 9-12
  • |
  • Duration: Two class periods

Lesson Plan Sections


At the conclusion of this lesson, students will:
1. identify the factors that have historically led Americans to war, and the ways in which these factors have interacted to influence the decision to go to war; and
2. understand the unique role of the president as commander in chief in determining U.S. involvement in armed conflicts.


The class will need the following:
U.S. history textbooks
Copies of the Take-Home Activity Sheet: American Wars: Contributing Factors


1. Begin by asking students to brainstorm reasons that the United States has gone to war throughout its history. Encourage students to think about why the United States decided to go to war in World War II, Vietnam, and the Persian Gulf. Write students' answers on the chalkboard.
2. Explain that historically our country has gone to war based on the interplay of several key factors. The president, Congress, external events, American interests, and public opinion have all played roles in determining whether the country should go to war. Share with students the following five key factors, either by writing them on the board or by displaying them on an overhead projector. Encourage students to take notes.
  • The president's view of the conflict: In some cases, the president has been eager for the United States to join a military conflict; for example, President James Polk initiated the Mexican War. President Franklin Delano Roosevelt was eager to support Britain and France and to quell threats from Germany in World War II. In other cases, the president has been hesitant to enter military conflict; for example, President James Madison was reluctant to involve the United States in the War of 1812.
  • The views of members of Congress: Members of Congress, specifically the so-called war hawks, were overwhelmingly in favor of American involvement in the War of 1812. Congress strongly supported the Spanish-American War of 1898 but was deeply divided over American involvement in World War I (even though it voted for the country to enter that war). The United States entered the Korean and Vietnam Wars even though Congress never officially declared war.
  • Events that involve Americans: The Japanese attack on Pearl Harbor in World War II immediately involved the United States in that war. In 1846, when Mexican soldiers crossed the Rio Grande and clashed with U.S. General Zachary Taylor's troops, President Polk used the skirmish to justify a war with Mexico.
  • American interests in the conflict: Americans have fought for land, as in the War of 1812; for oil, in the Persian Gulf War; for human rights, to some degree, in World War II and the Persian Gulf War; and for democracy, in the Korean and Vietnam Wars. Americans have also entered war to support their allies, as they did in World Wars I and II.
  • Public opinion: American involvement in the Spanish-American War was wildly popular. Many Americans, however, opposed the Vietnam War.
3. Explain to students that for the next few days they will analyze how the key factors listed above contributed to eight wars in United States history: the War of 1812, the Mexican War, the Spanish-American War, World War I, World War II, the Korean War, the Vietnam War, and the Persian Gulf War.
4. Assign one of the eight wars to each student. Have the class count off from one through eight and assign all "ones" the War of 1812, "twos" the Mexican War, and so forth. There should be at least two or three students in the class studying each war.
5. Pass out copies of the Take-Home Activity Sheet: American Wars: Contributing Factors. Students will need to complete the required information as homework. Students should use their U.S. history textbooks and other resources if necessary to complete the take-home sheet.
6. When students return to class, separate them into "expert groups," or groups made up of students who have worked on the same war. For instance, all students who have worked on the War of 1812 for homework will be in one group, all students who have worked on the Spanish-American War will be in another group, and so on.
7. Explain to students that while they are in their expert groups they should be discussing, and in some cases expanding upon, their answers on the take-home activity sheet. Explain that when they have finished, each group will be asked to teach the class what they have learned about the war they researched.
8. Each group should spend no longer than 5-10 minutes of class time on its presentation. The rest of the class should take detailed notes during the presentations and should be encouraged to ask questions of the presenters.
9. When the presentations have been completed, review with students what they have learned. Moderate a class discussion that compares and contrasts the eight wars studied. Can any conclusions be drawn about when and why Americans have gone to war? Work with students to identify recurring issues that have led to U.S. involvement in wars. Be sure to talk about the unique role of the president as commander in chief in each situation.

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Allow younger students to work on the activity sheet in small groups in class so that you may assist them as necessary. Review the chart before asking students to think about generalizations they can make. You may need to guide them toward drawing conclusions with specific questions, such as "How important is the president's view in determining whether or not we will go to war?"

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Discussion Questions

1. Debate whether or not the president, acting as commander in chief, should be able to use military force abroad without the consent of Congress, which has the constitutional authority to declare war.
2. In today's society, military troops can mobilize almost instantaneously, while in the past it could take months to prepare for war. Discuss how the speed at which society communicates and travels affects warfare. Do presidents even have time to debate the issue before taking military action?
3. The American people are asked to support a war with their taxes and their lives. Should public opinion play a role in the decision to go to war?
4. Analyze changes in the role of Congress in determining when the United States goes to war. How has this role changed, especially since World War II?
5. Discuss when the president should use military force. What events or issues justify the United States' going to war?
6. How should those who oppose going to war on religious, moral, or political grounds be treated?

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Have students turn in their completed take-home sheets to be evaluated. You may use the following rubric when evaluating student work:
  • Three points: accurate completion of the chart; strong contribution to the group presentation; evidence of understanding of the historical examples; astute conclusions about, and perhaps even critical analysis of, the war studied
  • Two points: failure to complete the chart accurately; some contribution to the group presentation; thoughtful conclusions but evidence of lack of thorough understanding of the information; evidence of lack of real analysis
  • One point: incomplete work with many inaccuracies

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Opposition to War
Ask students to research the history of opposition to war throughout U.S. history. Students might examine the beliefs and actions of conscientious objectors, religious peace sects and churches, pacifist organizations, peace movements, draft resisters, and pacifist leaders such as abolitionist William Lloyd Garrison and Jeannette Rankin, the first woman elected to Congress. Students could begin by reading Henry David Thoreau's essay "Civil Disobedience" and discussing the use of nonviolent resistance and civil disobedience.

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Suggested Readings

Persian Gulf War
Kathryn Gay and Martin Gay. Twenty First Century Books, 1996.
For a brief overview of the invasion of Kuwait by Iraq under Saddam Hussein, and the involvement of the United States in the ensuing Persian Gulf War, this is a solid choice. Direct quotations of those involved in the war add to the text.

The U. S. Presidency
Don Nardo. Lucent Books, 1995.
The president of the United States is called on to assume a number of powerful roles, including that of commander in chief. The president also leads the country in its relationships with foreign nations. A clear description of the varied duties of the president and how they have evolved over the life of our nation are effectively presented here.

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Definition: To overcome the anger, distrust, or animosity of; to appease or placate.
Context: In an attempt to avoid war, the British tried toconciliatethe United States.

Definition: The practice or skill of conducting negotiations between nations or governments
Context: Oncediplomacyfailed, the president decided it was time to use military force.

Definition: To assemble (resources, facilities, or the like) and make ready for action, as in time of war.
Context: The president ordered the immediatemobilizationof U.S. troops.

Definition: The foreign policy of a nation that refuses to take sides in an international dispute.
Context: The president publicly favored a policy ofneutralityalthough he was inclined to favor the British.

Definition: An act of aggression; hostile action; assault.
Context: The general planned another majoroffensiveagainst the enemy.

Definition: An action taken by one or more nations and designed to force another nation to comply with a legal, ethical, or moral code.
Context: While Congress favored the use ofsanctions, the president felt they were not enough.

war hawk
Definition: One who advocates war, especially any member of the 12th U.S. Congress who favored war.
Context: Thewar hawksin Congress argued for war with Great Britain.

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This lesson plan may be used to address the academic standards listed below. These standards are drawn from Content Knowledge: A Compendium of Standards and Benchmarks for K-12 Education: 2nd Edition and have been provided courtesy of theMid-continent Research for Education and Learningin Aurora, Colorado.
Grade level: 9-12
Subject area: Historical Understanding
Understands and knows how to analyze chronological relationships and patterns.
Understands historical continuity and change as it relates to a particular development or theme (e.g., the Industrial Revolution and the evolution of democracy in the United States).

Grade level: 9-12
Subject area: United States History
Understands the United States' territorial expansion between 1801 and 1861 and how it affected relations with external powers and Native Americans.
Understands the initiating factors and outcomes of the Mexican War (e.g., the extent to which President Polk bore responsibility for initiating the war, whether the war was justified, arguments for and against the war, and the impact of the Treaty of Guadalupe Hidalgo on the United States and Mexico).

Grade level: 9-12
Subject area: United States History
Understands developments in foreign policy and domestic politics between the Nixon and Clinton administrations.
Understands the influence of U.S. foreign policy on international events from Nixon to Clinton (e.g., the United States' role in the evolving political struggles in the Middle East, Africa, Asia, and Latin America; foreign policy in the post-Cold War era; U.S. goals and objectives in the Middle East; the pros and cons of U.S. intervention in the Persian Gulf under Reagan and Bush; and the role of human rights in American foreign policy).

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Lara Maupin, social studies teacher, Thomas Jefferson High School for Science and Technology, Alexandria, Virginia.

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