Name one war fought by the United States in the 1900s.

Answers from the USCIS list

Give one of these answers. Words in light (parentheses) are optional.

• World War I
• World War II
• Korean War
• Vietnam War
• optional: (Persian) Gulf War

Our explanation

“The 1900s” means the years 1900 to 1999. U.S. wars in those years include World War I, World War II, the Korean War, the Vietnam War, and the Persian Gulf War. Name one. The Civil War was in the 1800s.

Remember it

Both World Wars were in the 1900s. Either one is a correct answer.

Source

USCIS 2025 Study Guide (M-1175) p. 63: “World War I is one war fought by the United States in the 1900s.” Other 1900s wars listed: World War II, Korean War, Vietnam War, (Persian) Gulf War. p. 59: the Civil War is “one war that the U.S. fought during the 1800s.”

• Civics (History and Government) Questions for the Naturalization Test (2008 version), rev. 08/21 (PDF, USCIS)

Last checked on September 29, 2026.

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Easy to mix up with

• 72Name one war fought by the United States in the 1800s.