Visayas Mindanao The Battle of Caloocan was one of the opening engagements of the Philippine–American War, and was fought between an American force under the command of Arthur MacArthur Jr. and Filipino defenders led by Antonio Luna in February 1899.

Later, allegations that U.S. troops had committed atrocities such as summarily executing Filipino prisoners of war during the battle were investigated by a Senate Committee on the Philippines, which chose not to pursue the matter further.

Otis also argued that capturing Caloocan would serve the dual purpose of occupying a key settlement and trapping elements of the Philippine Revolutionary Army in Manila Bay, a viewpoint which was also shared by MacArthur Jr.[13] On February 10, a detachment of the 6th Field Artillery Regiment, along with the protected cruiser USS Charleston and monitor USS Monadnock (provided to MacArthur Jr. by United States Navy Admiral George Dewey) launched a preparatory bombardment of Filipino redoubts in Caloocan, which lasted for roughly three hours.

[14] The highest-ranking commander of Filipino troops in Caloocan (numbering roughly 5,000 strong) was Antonio Luna, whose soldiers were among those who had been pushed out of their entrenched positions by American forces near Manila on February 5.

Led by Major J. Franklin Bell, a company of the 1st Montana Volunteer Infantry Regiment snuck into Caloocan from the east and attacked Filipino positions in their rear.

A detachment of Filipino troops made a last stand at the Caloocan Cathedral, leading to an intense but short close-quarters engagement where American forces managed to rout the defenders.

[19] On February 22, Filipino forces under the command of Luna and Mariano Llanera launched an attack on American positions in Manila as part of the Second Battle of Caloocan, aiming to recapture the city.

[19] The conduct of American forces during and after the battle came under scrutiny following allegations by some U.S. soldiers that certain senior officers, including Wilder Metcalf, had ordered the summary execution of Filipino prisoners of war.

[20] Several American soldiers testified to the United States Senate Committee on the Philippines that they overheard a Captain Bishop, a subordinate of Metcalf, discussing no quarter orders issued by his superiors.

An American soldier, Cyrus Ricketts, testified to the committee's members that "several Filipinos in a trench near the dummy line" were summarily executed by U.S. forces after the battle.