Military Conflicts in U.S. History

Updated August 5, 2020 | Infoplease Staff

This page provides information about military conflicts involving the United States; including the American Revolution, the War of 1812, the Indian Wars, Dominican Republic, Bosnia, and more.

American Revolution (1775-1783) Great Britain forced its 13 American colonies to pay taxes but did not give them representation in the British Parliament. This and other injustices led the colonies to declare independence on July 4, 1776. Independence was achieved in 1783, when the Treaty of Paris was signed with Britain.

War of 1812 (1812-1815) British interference with American trade, impressment of American seamen, and “war hawks“ in Congress calling for western expansion into British territory led to war. At the war's conclusion, trade issues remained unresolved, but Britain gave up some of its territorial claims on the continent.

Mexican War (1846-1848) The U.S. annexation of Texas, and its stated desire to acquire California and other Mexican territory, precipitated this war. Mexico was forced to give up two-fifths of its territory. This land eventually became the states of California, Nevada, Arizona, New Mexico, and Utah.

Civil War (1861-1865) Economic and political rivalry between an agrarian South and an industrial North grew into a civil war fought over slavery and states' rights. Eleven states seceded from the Union to form the Confederate States of America. The Union victory led to the reunification of the country and ended slavery.

Indian Wars (colonial era to 1890) U.S. expansionism led to numerous military conflicts with the indigenous inhabitants of North America, forcing them to give up their land. The massacre at Wounded Knee, S.D., in 1890 is generally considered the last of these conflicts.

Spanish American War (1898) The U.S. supported Cuba's desire for independence from Spanish rule, and seized the opportunity to expand U.S. powers in other parts of the world. At the end of the brief conflict, Cuba gained its independence, and the U.S. gained several former Spanish territories: Puerto Rico, Guam, and the Philippines.

World War I (1914-1918) Rivalries over power, territory, and wealth led to the “Great War.“ In 1917, the U.S. joined the Allies (Britain, France, Russia, Italy, and Japan), who were at war with the Central Powers (Germany, Austria-Hungary, Bulgaria, and Turkey), after German submarines began sinking unarmed ships.

World War II (1939-1945) The Axis powers-Germany, Italy, and Japan-attempted to dominate the world. The Allies (U.S., Britain, France, USSR, and others) fought to stop them. The United States entered the war in 1941, after Japan's attack on Pearl Harbor. Germany surrendered in 1945, and Japan surrendered later that same year, after the U.S. dropped the atomic bomb on the cities of Hiroshima and Nagasaki.

Korean War (1950-1953) Communist North Korea, supported by China, invaded non-communist South Korea. UN forces, principally made up of U.S. troops, fought successfully to protect South Korea. The Korean War was the first armed conflict in the global struggle between democracy and communism, called the cold war.

Bay of Pigs (1961) The U.S. orchestrated the invasion, an unsuccessful attempt by Cuban exiles to overthrow Fidel Castro's communist regime in Cuba.

Vietnam War (1961-1973) In 1955, communist North Vietnam invaded non-communist South Vietnam in an attempt to unify the country and impose communist rule. The United States joined the war on the side of South Vietnam in 1961, but withdrew combat troops in 1973. In 1975 North Vietnam succeeded in taking control of South Vietnam.

Dominican Republic (1965) President Lyndon Johnson sent marines and troops to quash a leftist uprising in the Dominican Republic, fearing the island nation would follow in the footsteps of Cuba and turn communist.

Lebanon (1982-1984) U.S. troops formed part of a multinational peacekeeping force to help the fragile Lebanese government maintain power.

Grenada (1983) President Reagan invaded the Caribbean nation of Grenada to overthrow its socialist government, which had close ties with Cuba.

Panama (1989) President George H.W. Bush invaded Panama and overthrew Panamanian dictator and drug-smuggler Manuel Noriega.

Gulf War (1991) Iraq invaded Kuwait, and a U.S.-led multinational force came to Kuwait's aid and expelled Iraqi dictator Saddam Hussein's forces.

Somalia (1993) A U.S.-led multinational force attempted to restore order to war-torn Somalia so that food could be delivered and distributed within the famine-stricken country.

Bosnia (1994-1995) During the Bosnian civil war, which began shortly after the country declared independence in 1992, the U.S. launched air strikes on Bosnia to prevent “ethnic cleansing,“ primarily by Serbs against Bosnians. The U.S. became a part of NATO's peacekeeping force in the region.

Kosovo (1999) Yugoslavia's province of Kosovo erupted into violence in the spring of 1999. A U.S.-led NATO force intervened with air strikes after Slobodan Milosevic's Serbian forces uprooted the population and embarked on the ethnic cleansing of Kosovo's ethnic Albanian population.

Global War on Terror (2001- ) In the immediate aftermath of the Sept. 11, 2001, terrorist attacks, President George Bush launched the Global War on Terrorism-which has become the longest period of continuous war in U.S. history. The United Kingdom, several NATO countries, and other nations have participated to eliminate al-Qada and other militants groups.

Afghanistan (2001-2014) The Taliban government harbored Osama bin Laden and the al-Qaeda terrorist group, responsible for the Sept. 11, 2001, attacks on the United States. After Afghanistan refused to turn over Bin Laden, the U.S. and UN coalition forces invaded. The Taliban government was ousted and many terrorist camps in Afghanistan were destroyed. U.S. and NATO troops remain in Afghanistan to support its fragile new government.

Iraq War (2003-2010) The U.S. and Great Britain invaded and toppled the government of dictator Saddam Hussein. Troops remain in Iraq to combat the insurgency that formed after Hussein's defeat.

War Against the Islamic State (ISIS) (2014—) The Islamic State of Iraq and Syria (ISIS), also called Islamic State of Iraq and the Levant (ISIL), has terrorized large swaths of Iraq and Syria in its drive to establish an Islamic state in the Middle East ruled by strict shariah law. The militant group is made up of fundamentalist Sunni Muslims and foreign jihadists. In September 2014, President Barack Obama authorized airstrikes against ISIS in Syria. He was clear that he does not plan to deploy ground troops in the fight against ISIS.