One direct answer: The United States fought several major wars in the 1900s, including World War I (1917–1918), World War II (1941–1945), the Korean War (1950–1953), the Vietnam War (roughly 1955–1975), and the Gulf War (1990–1991).
If you’d like, I can expand on each war with causes, key events, and outcomes, or tailor the list to a specific aspect (e.g., dates, major battles, or casualties).
