United States Department of Defense - History & Wars

1700s

The Continental Army was created on 14 June 1775 by the Continental Congress as a unified army for the states to fight Great Britain, with George Washington appointed as its commander. George Washington, although not a great tactician, made use of the Fabian strategy and used hit-and-run tactics, hitting where the enemy was weakest, to wear down the British forces and their Hessian mercenary allies. With a decisive victory at Yorktown, and the help of French, Spanish and Dutch, the Continental Army prevailed against the British, and with the Treaty of Paris, the independence of the United States was acknowledged.

After the war, though, the Continental Army was quickly disbanded as part of the Americans' distrust of standing armies, and amateur state militias became the new nation's sole ground army, with the exception of one battery of artillery guarding West Point's arsenal. However, because of continuing conflict with American Indians, it was soon realized that it was necessary to field a trained standing army. The first of these, the Legion of the United States, was established in 1791.

1800s

The War of 1812 (1812-1815), the second and last American war against the British, was mostly a series of defeats for the US Army. An invasion of Canada completely failed, and US troops were unable to stop the British from burning the new capital of Washington, D.C.. However, the Regular Army, under Generals Winfield Scott and Jacob Brown, proved they were professional and capable of defeating a British army in the Niagara Campaign of 1814. Two weeks after a treaty was signed, though, Andrew Jackson defeated the British invasion of New Orleans. However this had little effect, as per the treaty both sides returned to the status quo.

Between 1815 and 1860, a spirit of Manifest Destiny struck the United States, and as settlers moved west the US Army engaged in a long series of skirmishes and battles with American Indians the colonists uprooted. The US Army also fought the short Mexican–American War, which was a victory for the United States and resulted in the new territories of California, Nevada, Utah, Colorado, Arizona, Wyoming and New Mexico.

The Civil War (1861-1865) was the most costly war for the United States. After most states in the South seceded to form the Confederate States of America, CSA troops opened fire on the US fort Fort Sumter in Charleston, South Carolina, starting the war. For the first two years Confederate forces solidly defeated the US Army, but after the decisive Battle of Gettysburg combined with superior industrial might and numbers, Union troops fought a brutal campaign through Confederate territory and the war ended with a Confederate surrender at Appomatox Courthouse in April 1865. Based on 1860 census figures, 8% of all white males aged 13 to 43 died in the war, including 6% in the North and an extraordinary 18% in the South.

Following the Civil War, the US Army fought a long battle with American Indians, who resisted US expansion into the center of the continent. But by the 1890s the US saw itself as a potential player internationally. US victories in the Spanish-American War (1898) and the more unknown and controversial Philippine-American War (1898-1913), as well as US intervention in Latin America and the Boxer Rebellion, gained America more land and international prestige.

1900s

The United States joined World War I (1914-1918) in 1917 on the side of Britain and France. Millions of US troops were sent to the front and were instrumental in the push that finally broke through the German lines. With victory on November 11, 1918, the Army once again decreased its forces.

The US joined World War II after the Japanese attack on Pearl Harbor in December 1941. On the European front, US Army troops made up large portions of the forces that captured North Africa, Sicily, and Italy. On D-Day and in the subsequent liberation of Europe and defeat of Germany, the millions of US Army troops played a central role. In the Pacific, Army soldiers participated alongside US Marines in the "island hopping" campaign that wrested the Pacific islands from Japanese control. Following the Axis surrenders in May and September of 1945, Army troops were deployed to Japan and Germany to occupy the two nations.
Korea. Soldiers of the 2nd Infantry Division man a machine gun.
Korea. Soldiers of the 2nd Infantry Division man a machine gun.

However, the end of World War II set the stage for the West-East confrontation known as the Cold War (late 1940s to late 1980s/early 1990s). Millions of US troops remained stationed in West Germany and across Europe until the 1990s in anticipation of Soviet attack.

During the Cold War, American troops and their allies fought Communist forces in Korea and Vietnam. (See Domino Theory.) The Korean War began in 1950. Under a United Nations umbrella, hundreds of thousands of US troops fought to prevent the takeover of South Korea by North Korea, and later, to invade the northern nation. After repeated advances and retreats by both sides, and the Peoples' Republic of China's entry into the war, a cease-fire returned the peninsula to the status quo in 1953.
Dak To, South Vietnam. An infantry patrol moves up to assault the last Viet Cong position after an attempted overrun of the artillery position by the Viet Cong during Operation Hawthorne.
Dak To, South Vietnam. An infantry patrol moves up to assault the last Viet Cong position after an attempted overrun of the artillery position by the Viet Cong during Operation Hawthorne.

The Vietnam War is often regarded as a low point in the Army's record. While American forces had been stationed in the Republic of Vietnam since 1959, they did not deploy in large numbers until 1965, after the Gulf of Tonkin Incident. American forces struggled to counter the guerrilla tactics of the communist Viet Cong and the North Vietnamese Army until 1973, when domestic political opposition to the war finally forced a US withdrawal. Two years later, the country was unified under a communist government.

The 1980s was mostly a decade of reorganization. The Army converted to an all-volunteer force with greater emphasis on training and technology. The Goldwater-Nichols Act of 1986 created Unified Combatant Commands bringing the Army together with the other four US armed forces under unified, geographically organized command structures. The Army also played a role in the invasions of Grenada in 1983 (Operation Urgent Fury) and Panama in 1989 (Operation Just Cause).

By 1991 Germany was reunited and the Soviet Union was near collapse. The Cold War was, effectively, over. Then Iraq invaded its tiny neighbor, Kuwait, and a US-led coalition deployed over 500,000 troops, the bulk of them from US Army formations, to drive out Iraqi forces. The war ended in convincing victory for the Army, as western coalition forces routed an Iraqi Army organized along Soviet lines in just one hundred hours.

After the Gulf War, the Army did not see major combat operations for the remainder of the 1990s. Army units did participate in a number of peacekeeping activities, such as the UN peacekeeping mission in Somalia in 1993, where the abortive Operation Gothic Serpent led to the deaths of eighteen American soldiers and the withdrawal of international forces. The Army also contributed troops to a NATO peacekeeping force in former Yugoslavia in the middle of the decade.

21st century
U.S. soldiers take cover during a firefight with insurgents in the Al Doura section of Baghdad March 7, 2007
U.S. soldiers take cover during a firefight with insurgents in the Al Doura section of Baghdad March 7, 2007

After the September 11, 2001 terrorist attacks and as part of the Global War on Terror, US and NATO forces invaded Afghanistan in 2001, replacing the Taliban government. Much more controversially, the US and other nations invaded Iraq in 2003 and quickly defeated the Saddam Hussein dictatorship, his military lacking training and inadequately equipped, most soldiers poorly paid and unmotivated. In the following years the war has arguably bogged down into another counter-insurgency campaign, with large numbers of suicide bomb attacks and the loss of almost 4,000 US servicemen and thousands more injured and paralysed. The lack of stability in the theater of operations has led to longer deployments for Regular Army as well as Reserve and Guard troops. However, some measure of success has been achieved such as the capture of Saddam Hussein and the holding of democratic elections.