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

Answers from the USCIS list

Give one of these answers.

• Easy answer to learnWar of 1812
• Mexican-American War
• Civil War
• Spanish-American War

Our explanation

“The 1800s” means the years 1800 to 1899. U.S. wars in those years include the War of 1812, the Mexican-American War, the Civil War, and the Spanish-American War. World War I was in the 1900s.

Remember it

Easiest: the War of 1812 — its year is in its name.

Source

USCIS 2025 Study Guide pp. 56, 59, 63. Quote (p. 56): “The Mexican-American War was one war fought by the United States in the 1800s.” Sidebar: “War of 1812, Civil War, Spanish-American War.”

• 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

• 78Name one war fought by the United States in the 1900s.
• 73Name the U.S. war between the North and the South.