The largest confirmed massacre of civilians by U.S. forces in the 20th century, exposing war crimes in Vietnam and fueling domestic opposition to the war.
Key Facts
- Civilian deaths
- 347–504 unarmed civilians killed
- Perpetrating units
- C Company and B Company, 23rd (Americal) Division
- Soldiers charged
- 26 soldiers charged with criminal offenses
- Only conviction
- Lt. William Calley Jr., found guilty of murdering 22 villagers
- Sentence served
- 3.5 years under house arrest after life sentence commuted
- Public disclosure
- Revealed by Ronald Ridenhour and Seymour Hersh in November 1969
By the Numbers
Location
Cause → Event → Consequence
On 16 March 1968, C Company entered Mỹ Lai 4 expecting to engage the Viet Cong's Local Force 48th Battalion. Operating under a climate of free-fire zones, body-count pressures, and widespread racism, soldiers found no enemy combatants but began killing anyway. The absence of guerrillas did not halt the operation, which continued under orders from Captain Ernest Medina.
U.S. Army soldiers of C Company and B Company systematically murdered between 347 and 504 unarmed Vietnamese civilians — mostly women, children, and elderly men — in the hamlets of Mỹ Lai 4 and Mỹ Khê 4. Villagers were rounded up and massacred with automatic weapons, bayonets, and grenades; one large group was executed in an irrigation ditch. Homes were burned, wells poisoned, and livestock slaughtered.
The massacre was initially covered up as a military victory, but journalist Seymour Hersh and veteran Ronald Ridenhour exposed it in November 1969, provoking global outrage. Only Lieutenant William Calley was convicted, serving just three and a half years under house arrest. The revelations intensified domestic opposition to the Vietnam War and prompted the Pentagon to establish the Vietnam War Crimes Working Group, which documented numerous additional atrocities.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Captain Ernest Medina, Lieutenant William Calley Jr., Warrant Officer Hugh Thompson Jr. (intervened against the massacre).
Side B
1 belligerent