| War in Afghanistan | 2001–2021 | U.S.-led coalition vs. the Taliban; ended with U.S. withdrawal. |
| Gulf War | 1990–1991 | U.S.-led coalition expelled Iraq from Kuwait. |
| Vietnam War | 1955–1975 | North Vietnam vs. South Vietnam and the U.S.; ended in reunification under the North. |
| Korean War | 1950–1953 | North Korea and China vs. South Korea and UN forces; ended in armistice. |
| World War II | 1939–1945 | Allies vs. Axis; deadliest conflict in human history. |
| World War I | 1914–1918 | Allies vs. Central Powers; ended with the Treaty of Versailles. |
| American Civil War | 1861–1865 | Union vs. Confederacy; Union victory ended slavery in the U.S. |
| Crimean War | 1853–1856 | Russia vs. an alliance of Britain, France, and the Ottoman Empire. |
| Napoleonic Wars | 1803–1815 | France under Napoleon vs. shifting European coalitions; ended at Waterloo. |
| American Revolutionary War | 1775–1783 | Thirteen Colonies won independence from Great Britain. |
| Seven Years' War | 1756–1763 | Global conflict pitting Britain and Prussia against France, Austria, and Russia. |
| English Civil War | 1642–1651 | Royalists vs. Parliamentarians; led to the execution of Charles I. |
| Thirty Years' War | 1618–1648 | Catholic vs. Protestant powers in Europe; ended by the Peace of Westphalia. |
| Hundred Years' War | 1337–1453 | England vs. France over the French throne; France ultimately prevailed. |
| Punic Wars | 264–146 BC | Rome vs. Carthage; Rome won and destroyed Carthage. |
| Peloponnesian War | 431–404 BC | Athens vs. Sparta; Sparta prevailed, ending Athenian dominance. |