The Vietnam War caused enormous rifts at home and abroad. How much do you know about this debacle of a conflict?
South Vietnam sent its best units to attack the Communists and failed for days. The Communists were eventually driven out, but the battle was a stinging blow to South Vietnam's forces.
The Communists learned to attack at close range in order to counter air support and artillery. They used these tactics successfully throughout the war.
In 1968, the North Vietnamese started a siege of U.S. forces at Khe Sahn. The battle lasted for more than five months.
More than two months of fighting killed about 500 Marines. By some estimates, the North Vietnamese lost around 10,000.
After months of withstanding the siege, the Americans gave up and abandoned the base. Both sides called it a victory, but the North Vietnamese were the ones who retook territory.
In September 1965, the Marines started Operation Piranha. They lost two men but killed nearly 200 Communist soldiers.
The Battle of Hue started thanks to an offensive launched by the Communists. Although the Communists were driven back, they scored a major propaganda victory.
As many as 5,000 civilians were killed during the Battle of Hue, an engagement that took place right in the city of Hue. The city was almost entirely destroyed during the battle.
The Battle of Hamburger Hill happened as part of Operation Apache Snow. The Americans captured Hamburger Hill with a risky direct assault and then promptly abandoned their gains, leading Americans to wonder what the war was all about.
The 10-day battle accomplished virtually nothing from a strategic standpoint and resulted in massive public backlash against military leadership.
The Battle of Ap Bac happened at the very beginning of 1963. It was a small-scale battle that resulted in a Viet Cong victory.
The Viet Cong managed to shot down five U.S. helicopters during the Battle of Ap Bac. In the aftermath of this early battle, the Americans realized that they'd have to become more involved in the conflict in order to defeat the Viet Cong.
Operation MacArthur was part of the Battle of Dak To. The operation was meant to provide reinforcements for American and South Vietnamese forces, which eventually achieved a tactical victory.
The Battle of Van Tuong was also known as Operation Starlite. It was the first major offensive conducted by U.S.-only personnel.
During this operation, American forces only carried two gallons of water per man, which wasn't nearly enough in the stifling Vietnamese heat. Resulting dehydration made life even harder for the American soldiers.
Only 24 Americans were a part of the Battle of Lang Vei, but almost all of them became casualties or prisoners. The North Vietnamese victory included the first major use of armored forces in the war.
The Viet Cong and North Vietnamese suffered heavy casualties during the offensive, but strategically their plan worked. Their limited successes drained U.S. resolve for the war effort.
They launched the huge Tet Offensive on January 31, 1968. The offensive was so named because of the lunar new year holiday called Tet.
The Tet Offensive attacked about 100 towns with roughly 70,000 Viet Cong and North Vietnamese soldiers. The offensive was a turning point for the war, which the U.S. eventually lost.
The Americans launched thousands of bomber sorties to pummel the Communists into submission. Effective anti-aircraft weapons helped the Communists punish the American offensive.
The Communists blasted more than 900 U.S. aircraft during the operation. In just one year (1967), the U.S. lost more than 360 aircraft.
The Communists drove American forces out of the area and destroyed nine U.S. aircraft in the process. Hundreds of South Vietnamese soldiers died in defeat, too.
In 1975, the Communists attacked and captured Xuan Loc. Their successes helped them approach Saigon, which they eventually conquered to end the war.
The 11-day bombing campaign involved hundreds of sorties and tens of thousands of bombs, which severely damaged Communist resources and killed more than 1,000 civilians.
The First Battle of Khe Sanh is better known as the Hill Fights, as it occurred on the hills north of America's Khe Sanh base. More than 150 Marines died, but they killed nearly 1,000 enemies and won the battle.
The Communists launched the Easter Offensive in 1972, suffering heavy casualties but capturing large swaths of territory it used as a bargaining chip to end the war.
More than 130 Americans were ambushed by the North Vietnamese at Xa Cam My. The Communists were able to kill dozens of U.S. soldiers before slipping away.
South Vietnam suffered more than 200,000 casualties as it fought off the Communist offensive. Nearly a third of the South's army was destroyed during the offensive.
Operation Crimson Tide was the first operation of the war meant to rescue an American POW. The mission was a catastrophe, ending with 12 dead, 17 missing and no rescues.
The Battle of Fire Support Base Ripcord lasted for about three weeks, as Communist forces laid siege to outnumbered Americans. It was the last large engagement between these ground forces in the war.