U.S. Military History Timeline
57 events spanning 1775 to the present — filter by branch, conflict, or category.
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Showing 57 of 57 events
Continental Army Founded
The Second Continental Congress establishes the Continental Army on June 14, 1775, to coordinate the military efforts of the thirteen colonies. George Washington is appointed Commander-in-Chief.
Continental Navy & Marine Corps Founded
The Continental Congress authorizes the Continental Navy on October 13 and the Continental Marines on November 10, 1775, at Tun Tavern in Philadelphia.
Battle of Bunker Hill
On June 17, 1775, colonial militiamen repulse two British assaults before being driven from Breed's Hill in Boston. Though a tactical British victory, the battle demonstrates that colonial forces can stand against professional soldiers and stiffens Continental resolve.
Declaration of Independence
The Second Continental Congress adopts the Declaration of Independence on July 4, 1776, formally separating the thirteen colonies from Great Britain. Washington reads the Declaration to his troops in New York; four months later he wins the surprise victory at Trenton that saves the Continental Army.
Valley Forge
Washington's Continental Army endures a brutal winter encampment at Valley Forge, Pennsylvania (December 1777 – June 1778). Friedrich von Steuben, a Prussian officer, drills the army into a disciplined professional force. The survivors who march out in spring are a far more effective military than the one that entered.
Battle of Yorktown — Revolutionary War Ends
Franco-American forces trap British General Cornwallis at Yorktown, Virginia, in October 1781. The French fleet defeats the British at the Battle of the Chesapeake, cutting off Cornwallis's escape by sea. His surrender on October 19, 1781 effectively ends the Revolutionary War.
Treaty of Paris — Revolutionary War Ends
The United States and Great Britain sign the Treaty of Paris on September 3, 1783, ending the Revolutionary War and recognizing American independence.
Revenue Marine Founded (Coast Guard)
President George Washington signs legislation creating the Revenue Marine on August 4, 1790 — the forerunner of the U.S. Coast Guard.
Department of the Navy Established
Congress establishes the Department of the Navy as a separate cabinet-level department, reflecting the growing importance of naval power.
Quasi-War with France
The United States fights an undeclared naval war with Revolutionary France (1798–1800) over French seizures of American merchant ships. The conflict spurs the creation of the Department of the Navy and the Marine Corps as permanent institutions and produces the first significant U.S. naval victories.
West Point Founded
Congress authorizes the United States Military Academy at West Point, New York. The first class graduates on October 12, 1802.
Battle of Derna — First Overseas Victory
Marines and mercenaries led by Lt. Presley O'Bannon march 500 miles across the Libyan desert and storm the fortress of Derna on April 27, 1805, ending the First Barbary War. The victory — the first American military triumph on foreign soil — is commemorated in the Marines' Hymn: "to the shores of Tripoli."
War of 1812
The United States goes to war with Great Britain over maritime rights, trade restrictions, and British support for Native American tribes. Key battles include the Battle of Lake Erie and the burning of Washington, D.C.
U.S. Naval Academy Founded
Secretary of the Navy George Bancroft establishes the Naval School at Fort Severn in Annapolis, Maryland, on October 10, 1845.
Mexican-American War
The U.S. declares war on Mexico. American forces under Generals Zachary Taylor and Winfield Scott capture Mexico City. The Treaty of Guadalupe Hidalgo adds California and the Southwest to the United States.
Battle of Chapultepec
American forces under General Winfield Scott storm Chapultepec Castle — the Mexican Military Academy — on September 13, 1847, in the decisive battle of the Mexican-American War. A group of young Mexican cadets (Los Niños Héroes) fight to the death rather than surrender, becoming national heroes in Mexico.
American Civil War
The deadliest conflict in American history. Union forces ultimately defeat the Confederate States. Key battles include Gettysburg, Antietam, and the siege of Petersburg. The war ends with Lee's surrender at Appomattox.
Monitor vs. Virginia — Age of Ironclads
On March 9, 1862, the USS Monitor and CSS Virginia (Merrimack) fight to a draw in Hampton Roads, Virginia — the first battle between armored warships. The engagement renders wooden warships obsolete overnight and launches the age of the modern navy.
Battle of Gettysburg and Vicksburg
In the war's turning-point week (July 1–4, 1863), Union forces defeat Lee's second invasion of the North at Gettysburg while Grant captures Vicksburg, giving the Union complete control of the Mississippi River. Together these victories effectively end Confederate hopes of winning the war.
Coast Guard Academy Founded
The Revenue Cutter Service establishes the School of Instruction aboard the schooner Dobbin in New Bedford, Massachusetts — the origin of what would become the United States Coast Guard Academy. Unlike the other service academies, USCGA eventually adopted a merit-only admissions process requiring no congressional nomination.
Spanish-American War
A brief conflict triggered by the explosion of USS Maine in Havana harbor. Admiral Dewey's decisive victory at Manila Bay and the Rough Riders' charge at San Juan Hill make the U.S. a global power.
Battle of Manila Bay
Commodore George Dewey's Asiatic Squadron destroys the entire Spanish Pacific Fleet in Manila Bay on May 1, 1898, without losing a single American sailor. The victory launches the United States as a Pacific power and begins the American presence in the Philippines that would last until 1946.
Wright Brothers First Flight
Orville Wright makes the first powered heavier-than-air flight at Kitty Hawk, North Carolina, on December 17, 1903. The Army Signal Corps purchases the first military airplane in 1908, beginning the transformation of warfare that would culminate in the creation of the independent Air Force less than forty years later.
World War I
The United States enters WWI on April 6, 1917. The American Expeditionary Forces under General Pershing help break the stalemate on the Western Front. The Armistice is signed on November 11, 1918.
United States Enters World War I
Congress declares war on Germany on April 6, 1917, following unrestricted submarine warfare and the Zimmermann Telegram. General Pershing sails for France to build the American Expeditionary Forces; by war's end more than two million American soldiers will serve in France.
Meuse-Argonne Offensive
The largest offensive in American military history — 1.2 million U.S. soldiers attacking along a 40-mile front — begins September 26, 1918. Over 47 days, American and French forces break the Hindenburg Line and advance toward Germany. The German government requests an armistice on November 11, 1918 (the 11th hour of the 11th day of the 11th month).
World War II
Japan attacks Pearl Harbor on December 7, 1941, bringing the U.S. into WWII. American forces fight on two fronts. D-Day (June 6, 1944) opens a Western Front in Europe; Japan surrenders on August 15, 1945.
Attack on Pearl Harbor
Japanese carrier aircraft attack the U.S. Pacific Fleet at Pearl Harbor, Hawaii, on December 7, 1941, killing 2,403 Americans and destroying or damaging 19 warships and 328 aircraft. President Roosevelt calls it "a date which will live in infamy." Congress declares war on Japan on December 8; Germany and Italy declare war on the U.S. on December 11.
Battle of Midway
U.S. Navy carrier aircraft, guided by intelligence from broken Japanese naval codes, sink four Japanese fleet carriers at Midway (June 4–7, 1942), permanently reversing Japanese naval superiority in the Pacific. Planned by Admiral Nimitz, executed by Admirals Fletcher and Spruance, Midway is widely considered the turning point of the Pacific War.
Merchant Marine Academy Founded
The United States Merchant Marine Academy is formally established at Kings Point, New York in February 1943, at the height of the Battle of the Atlantic. Merchant mariners are dying at sea at rates comparable to combat service; the Academy exists to train the officers needed to crew the fleet supplying Allied forces worldwide. Seventeen Kings Point midshipmen die in action while still enrolled.
D-Day — Normandy Invasion
Operation Overlord launches on June 6, 1944, as 156,000 Allied troops cross the English Channel and assault five beaches in Normandy, France. Commanded by General Eisenhower, D-Day is the largest amphibious operation in history. Allied casualties are severe — particularly at Omaha Beach — but the lodgment is secured, opening the decisive Western Front in Europe.
Battle of the Bulge
Germany's last major offensive in the West (December 1944 – January 1945) creates a "bulge" in Allied lines through the Ardennes forest of Belgium and Luxembourg. The siege of Bastogne — where the 101st Airborne refuses to surrender despite encirclement — becomes an iconic act of American military resolve. Patton's Third Army pivots 90 degrees and relieves Bastogne in 48 hours.
National Security Act — Air Force Created
The National Security Act of 1947 establishes the U.S. Air Force as an independent service branch on September 18, 1947, separating from the Army Air Forces. It also creates the National Security Council and the CIA.
Military Desegregation — Executive Order 9981
President Truman signs Executive Order 9981 on July 26, 1948, ordering the desegregation of the U.S. Armed Forces — ending the policy of racially segregated units that had been in place since the Civil War. Implementation is gradual but the order transforms the military into one of America's first fully integrated institutions, years before the Civil Rights Act.
Berlin Airlift
When the Soviet Union blockades West Berlin in June 1948, the United States and Britain mount a massive airlift (June 1948 – May 1949) supplying the city by air. At its peak, Allied aircraft land every 90 seconds at Tempelhof Airport. The Soviets lift the blockade in May 1949, and the airlift demonstrates Western resolve in the emerging Cold War.
Korean War
North Korea invades South Korea on June 25, 1950. UN forces under General MacArthur push back, but Chinese intervention prolongs the conflict. An armistice is signed on July 27, 1953.
Inchon Landing — Korean War Turning Point
General MacArthur's amphibious landing at Inchon on September 15, 1950 — an operation his commanders considered nearly impossible — outflanks North Korean forces and leads to the recapture of Seoul within two weeks. The landing is one of the most daring operational strokes in American military history, executed against a harbor with extreme tidal variations.
Air Force Academy Founded
Congress authorizes the United States Air Force Academy. The first class enrolls in 1955; the permanent campus in Colorado Springs opens in 1958.
Cuban Missile Crisis
On October 22, 1962, President Kennedy reveals that Soviet nuclear missiles have been installed in Cuba and demands their removal. For thirteen days, the world stands on the edge of nuclear war. A naval quarantine prevents additional Soviet ships from reaching Cuba; the Soviets ultimately remove the missiles. The crisis is the closest the Cold War comes to nuclear exchange.
Vietnam War
U.S. involvement escalates after the Gulf of Tonkin Resolution (1964). At peak deployment, over 500,000 American troops serve in Vietnam. U.S. combat troops withdraw in 1973; Saigon falls in 1975.
Tet Offensive
On January 31, 1968, the first day of the Vietnamese Lunar New Year, the Viet Cong and North Vietnamese Army launch simultaneous attacks on more than 100 cities and towns across South Vietnam, including the U.S. Embassy in Saigon. The offensive is militarily repulsed, but its scale shatters American public confidence in government assurances that the war is being won.
Apollo 11 — First Moon Landing
On July 20, 1969, Neil Armstrong and Buzz Aldrin (West Point, 1951) land on the Moon. The mission fulfills President Kennedy's 1961 challenge and represents a major Cold War technological achievement.
All-Volunteer Military
The United States ends the draft and transitions to an all-volunteer military on July 1, 1973, following the Paris Peace Accords ending U.S. involvement in Vietnam.
Women Admitted to Service Academies
Congress passes legislation in 1975 requiring the admission of women to the federal service academies, effective 1976. The Coast Guard Academy had admitted women in 1975. The first women enter West Point, the Naval Academy, and the Air Force Academy in the summer of 1976 and graduate in the Class of 1980, permanently opening every service academy to women.
Beirut Barracks Bombing
On October 23, 1983, a suicide truck bomb destroys the U.S. Marine barracks at the Beirut International Airport, killing 241 American service members — the deadliest single-day death toll for the Marines since Iwo Jima. A simultaneous attack kills 58 French paratroopers. The bombing shapes American thinking about terrorism, force protection, and the risks of peacekeeping deployments.
Operation Just Cause — Panama
On December 20, 1989, the United States launches Operation Just Cause against Panama, deposing dictator Manuel Noriega. The operation features the first combat use of the F-117 stealth aircraft, the combat debut of Army Rangers in a major operation, and the first combat jump since the Korean War. Noriega surrenders on January 3, 1990.
Operation Desert Storm — Gulf War
A coalition of 34 nations under General H. Norman Schwarzkopf liberates Kuwait from Iraqi occupation in a 100-hour ground campaign following six weeks of air strikes. Iraq is defeated on February 28, 1991.
Battle of Mogadishu
On October 3–4, 1993, U.S. Army Rangers and Delta Force operators in Mogadishu, Somalia attempt to capture lieutenants of warlord Mohamed Farrah Aidid. Two Black Hawk helicopters are shot down; 18 Americans are killed and 73 wounded in an 18-hour urban battle. The engagement, made famous by Mark Bowden's book and the film *Black Hawk Down*, reshapes American attitudes toward military interventions in failed states.
September 11 Attacks
Al-Qaeda terrorists hijack four aircraft, attacking the World Trade Center and the Pentagon. Nearly 3,000 people are killed. The U.S. invokes Article 5 of the NATO treaty and launches the Global War on Terror.
War in Afghanistan
Following 9/11, the U.S. invades Afghanistan to dismantle al-Qaeda and remove the Taliban government. The war spans 20 years — the longest in American history. U.S. forces withdraw in August 2021.
Fall of Kabul — Operation Enduring Freedom
U.S. and coalition forces, working with Afghan Northern Alliance fighters, capture Kabul on November 13, 2001, six weeks after the 9/11 attacks. The Taliban government collapses within weeks; bin Laden escapes to Pakistan. The initial military success creates a nation-building challenge that will occupy American forces for the next two decades.
Iraq War
The U.S. invades Iraq on March 20, 2003, toppling Saddam Hussein. A prolonged insurgency follows. The surge strategy of 2007, led by General Petraeus, stabilizes the country. Combat operations end in 2011.
The Iraq Surge
President Bush announces the deployment of 30,000 additional troops to Iraq in January 2007, implementing the counterinsurgency strategy developed by General Petraeus and documented in FM 3-24. Combined with the Anbar Awakening (Sunni tribal leaders turning against al-Qaeda), violence in Iraq falls by more than 80% over the following eighteen months.
Osama bin Laden Killed
U.S. Navy SEALs from SEAL Team Six raid a compound in Abbottabad, Pakistan on May 2, 2011, killing Osama bin Laden — the founder of al-Qaeda and the architect of the September 11 attacks. The raid, authorized by President Obama, is conducted without Pakistani government knowledge and represents one of the most consequential special operations missions in American history.
Space Force Established
President Trump signs the National Defense Authorization Act on December 20, 2019, establishing the U.S. Space Force — the first new military branch since the Air Force in 1947.
Withdrawal from Afghanistan
The United States completes its withdrawal from Afghanistan on August 30, 2021, ending America's longest war at 20 years. The Taliban retake Kabul within days of the withdrawal's announcement, raising difficult questions about the results of two decades of counterinsurgency, nation-building, and the limits of military power to achieve political objectives.
Operation Epic Fury
On February 28, 2026, the United States and Israel launched Operation Epic Fury — a coordinated joint military campaign against Iran. The operation's stated objectives were to permanently destroy Iran's ballistic missile arsenal, dismantle its naval fleet in the Persian Gulf and Gulf of Oman, and eliminate its nuclear weapons development infrastructure. U.S. forces employed carrier strike groups, B-2 Spirit stealth bombers, F-35 strike packages, submarine-launched Tomahawk cruise missiles, and Special Operations assets operating in coordination with the Israel Defense Forces. The campaign represented the largest direct U.S. military action against a nation-state since the 2003 invasion of Iraq and the most significant joint U.S.-Israeli military operation ever conducted.
