The Balangiga massacre, as it is known in the Philippines, or the Balangiga affair, as it is known in the United States,was an incident in 1901 during the Philippine-American War where more than forty American soldiers were killed in a surprise guerrilla attack in the town of Balangiga on Samar island. This incident was described as the United States Army's worst defeat since the Battle of the Little Bighorn in 1876.
The subsequent retaliation by American troops resulted in the killing of 2000–3000 Filipinos on Samar, the majority of whom were civilians. The heavy-handed reprisal earned a court-martial for Gen. Jacob H. Smith, who had ordered the killing of everyone ten years old and over. Reprimanded but not formally punished, Smith was forced into retirement from the service because of his conduct.
The attack and the subsequent retaliation remains one of the longest-running and most controversial issues between the Philippines and the United States. Conflicting records from both American and Filipino historians have confused the issue. Demands for the return of the bells of the church at Balangiga, taken by the Americans as war booty and collectively known as the Balangiga bells, remain an outstanding issue of contention related to the war. One church bell remains in the possession of the 9th Infantry Regiment at their base in Camp Red Cloud, South Korea, while two others are on a former base of the 11th Infantry Regiment at F.E. Warren Air Force Base in Cheyenne, Wyoming.
According to some nationalist Filipino historians, the true "Balangiga massacre" was the subsequent American retaliation against the Samar population.