Q100: Which of the following was not a war fought by the United States in the 1900s?

A. World War I
B. World War II
C. Vietnam War
D. War in Afghanistan 

Question Background Information


For most of its history, the United States tended to follow George Washington’s advice to remain detached from military involvement on foreign shores, but this slowly changed over the course of the 20th century, during which the US engaged in five major wars. 

Both World War I and II began without US involvement, but attacks on American ships in the case of World War I, and on Pearl Harbor in World War II, eventually pulled America into these broader conflicts. World War II resulted in the defeat of the authoritarian regimes in Nazi Germany and imperial Japan. 

Although the United States avoided direct armed conflict with the communist Soviet Union during the 20th century, it did participate in both the Korean War and Vietnam War, each of which sought to minimize the spread of communist dictatorship. Finally, in the Persian Gulf War in 1991, America and its allies foiled the Iraqi dictator Saddam Hussein’s efforts to capture Kuwait.

Additional Content

Offline Activity


  • Provide each group with the reading Wars of the 1900s.          
  • Provide each group with the timeline and directions. 
    • Directions      
    • Page 1  
    • Page 2     
    • Page 3    
    • Page 4      
  • A rubric is provided if this is a graded activity.

Required Files

The Teaching Materials for this exercise includes a rubric (Q91 Rubric).

Teaching Materials.


  1. Have the students work in pairs. Divide the class into pairs based on the students’ individual levels. Group A is the group that needs some extra support. Group B is the core group that has the core knowledge to complete the activity. Group C is the enrichment group that has mastered the material. Group C students are prepared to extend their knowledge. Pair those who need support (Group A) with those who have core knowledge and/or have mastered the material (Groups B and C).  
    • This works equally well as an individual assignment. 
  2. Provide the students with the necessary materials.  
    • Explain that they are going to create an illustrated timeline that traces the major wars that the United States fought during the 1900s.  
    • The timeline will take four pages; each page is dedicated to a single war, which allows the students space to write as well as illustrate a scene from the war.  
      • The scene can be based on the reading or on prior knowledge about the war.  
  3. Circulate throughout the room as the students work on their timelines.  
    • Once the students are finished, provide them with transparent tape or glue to connect the four pages and create a single timeline.  
    • Hang the timelines up around the room.  

Discussion Prompts


During the 1900s, the way we fought wars changed drastically. The advances in technology that made Civil War combat more lethal than earlier wars only continued—whether with tanks and poison gas in World War I, aerial combat and bombers in World War II, or more recently precision-guided munitions. Why we fought wars has changed in some ways, too. While international affairs often involved America, such as the Napoleonic Wars pulling America into the War of  1812, or Cuban independence in the Spanish-American War, America’s growing role in international leadership over the 20th century has meant gradually increasing involvement in global conflict compared to the country’s earlier history.

Prompt 1

As it had in the 19th century, the United States fought several major wars in the 20th. Name one war that the U.S. fought in the 1900s. Why was this war fought? How did it affect the nation?

Prompt 2

There were five major wars in which the United States of America fought during the 1900s: World War I, World War II, the Korean War, the Vietnam War, and the Persian Gulf War. Which one do you believe had the most significant impact on the United States and why? Use current and past events to support your answer.