Which of these wars did the United States fight in the 1900s?

1. The wars the United States fought in the 1900s were World War I, World War II, the Korean War, the Vietnam War, and the Persian Gulf War. 2. The Persian Gulf War is on that list, so it is the answer. 3. The Mexican-American War belongs to the 1800s. 4. The Spanish-American War was fought in the 1800s as well. 5. The Civil War, between the North and the South, was also an 1800s war. 6. Every option names a real American war, so the century in the question is the only thing that decides the answer. _Source: USCIS Civics Flash Cards M-623 (rev. 02/12), public domain, official civics question 78_