March 13 – May 7, 1954 · North Vietnam Theater

The decisive battle that ended French rule in Indochina. General Giap surrounded a French garrison at a remote valley with 50,000 Viet Minh troops and, impossibly, hauled artillery over jungle mountains to shell the airstrip. Resupply became impossible. After 57 days, the surviving garrison of roughly 10,800 surrendered. France's defeat was total and humiliating.

November 14–18, 1965 · South Vietnam Theater

The first major battle between US Army troops and the North Vietnamese Army, fought in the central highlands. Air cavalry — helicopter-transported infantry — allowed Lt. Col. Hal Moore to move rapidly but also led to his 400-man battalion being surrounded by 2,000 NVA. Three days of savage fighting proved the NVA would stand and fight Americans directly, contrary to US expectations.

January 21 – July 9, 1968 · South Vietnam Theater

NVA forces besieged a US Marine base near the DMZ in the mountains near the Laotian border. Westmoreland, fearing another Dien Bien Phu, poured resources into holding it. As the world watched the siege, Giap launched the Tet Offensive against South Vietnam's cities — Khe Sanh had been the feint all along. The Marines held Khe Sanh, then abandoned it four months later.

January 30 – September 23, 1968 · South Vietnam Theater

During the Tet lunar new year holiday, 85,000 NVA and Viet Cong fighters simultaneously attacked more than 100 cities and towns across South Vietnam, including the US Embassy compound in Saigon. The attacks were militarily repulsed — Viet Cong forces were decimated and never recovered — but the footage of fighting inside the Embassy shocked Americans who had been told the war was being won.

January 31 – March 3, 1968 · South Vietnam Theater

Part of the Tet Offensive, NVA forces captured Hue — South Vietnam's ancient imperial capital — and held it for 26 days. House-by-house fighting through the old city and the Citadel cost hundreds of American and thousands of South Vietnamese casualties. During the occupation, NVA forces executed between 2,800 and 6,000 civilians and officials in mass graves discovered after the battle.

May 10–20, 1969 · South Vietnam Theater

US and South Vietnamese forces launched 11 frontal assaults over ten days to capture a heavily fortified NVA hilltop position in the A Shau Valley. 'Hamburger Hill' earned its nickname from soldiers who felt they were being fed into a meat grinder. The hill was taken on May 20th — and abandoned nine days later as having no strategic value.

March 30 – October 22, 1972 · South Vietnam Theater

North Vietnam's conventional invasion of South Vietnam with 120,000 troops and Soviet-supplied tanks. US ground forces had been largely withdrawn; South Vietnamese troops bore the brunt, supported by massive American air power. Nixon ordered B-52 strikes and the mining of Haiphong Harbor. The offensive was eventually repulsed at enormous cost, but revealed the South Vietnamese army's fragility without US air support.

April 29–30, 1975 · South Vietnam Theater

Two years after the Paris Peace Accords and two years after the last US combat troops left, North Vietnam launched its final offensive. South Vietnamese defenses collapsed within weeks. The US Embassy was evacuated by helicopter from the rooftop in chaotic scenes broadcast worldwide — South Vietnamese civilians desperately attempting to board the last helicopters, abandoned allies clinging to skids. NVA tanks crashed through the gates of the Presidential Palace on April 30th.