1. Revolutionary War (1775-1783): This war was fought against the British Empire and resulted in the independence of the United States of America.
2. War of 1812 (1812-1815): This war was fought against Great Britain and resulted in a restoration of pre-war boundaries and a stronger sense of national identity for the United States.
3. Mexican-American War (1846-1848): This war resulted in the expansion of the United States' territory, acquiring land in the present-day Southwest region.
4. Civil War (1861-1865): This war was fought between the Northern and Southern states of the United States over issues of slavery, states' rights, and economic interests. It ended with the reunification of the country under the authority of the federal government.
5. Spanish-American War (1898): This war was fought against Spain and resulted in the acquisition of territories such as Cuba, Puerto Rico, Guam, and the Philippines by the United States.
6. World War I (1917-1918): The United States entered World War I in 1917 and fought alongside the Allies against Germany and its allies.
7. World War II (1941-1945): The United States entered World War II in 1941 and played a significant role in the Allied victory against Nazi Germany and Imperial Japan.
8. Korean War (1950-1953): The United States intervened in the Korean War in support of South Korea against North Korea, resulting in a stalemate and the creation of the Korean Demilitarized Zone (DMZ).
9. Vietnam War (1954-1975): The United States provided military support and personnel to South Vietnam in the Vietnam War to resist the communist-backed North Vietnam.
10. Gulf War (1990-1991): This war was fought to liberate Kuwait after it was invaded by Iraq.
11. Iraq War (2003-2011): The United States, along with coalition forces, invaded Iraq to remove Saddam Hussein from power and address concerns about weapons of mass destruction.
12. War in Afghanistan (2001-2021): This was the longest war in U.S. history and involved the removal of the Taliban regime and efforts to establish a stable government in Afghanistan.
This list is not exhaustive, and the US has been involved in numerous other conflicts and military operations throughout its history.