American Revolutionary War (1775-1783) - This was the war that established the United States as an independent nation, and it fought against the British Empire. The war was marked by notable battles, such as the Battle of Bunker Hill and the Siege of Yorktown, and it was won against the Continental Army led by General George Washington.

Civil War (1861-1865) - This was a war between the northern states, known as the Confederacy, and the southern states, known as the Confederacy. The war broke out over issues like slavery and the rights of nations, and it led to the emancipation of slaves and the unification of the country.

World War II (1939-1945) - This is a global war involving many countries, including the United States. The war against the Axis powers was led by Germany, Japan, and Italy, and it had profound effects on the world, including the Holocaust and the use of the atomic bomb.

Each of these wars was important in its own right, and they all played a major role in shaping the history of the United States.