The US invaded the Philippines in 1898 with 40,000 troops which mushroomed to 126,000 by 1902. Pershing was commissioned there from 1898 until 1903. In 1901, Mark Twain wrote a polemic against colonialism titled “To the Person Sitting in Darkness” which cites an American soldier in the Philippines from a letter to his mother in Iowa: “We never left one alive. If one was wounded, we would run our bayonets through him.”
That letter is not the only testimony to brutalities against Filipino civilians by the US Army. Reports of extreme barbarism by US troops were so rampant that in 1902 the US Senate committee conducted an investigation committee of war crimes in the Philippines. The letters of many US soldiers describing atrocities were introduced at the hearing along with testimony by generals & military officers deployed there. Rohingya Muslims will recognize the methods employed: entire villages were torched; civilians were tortured, including by waterboarding; tens of thousands were herded into concentration camps; thousands were summarily executed.
Estimates of Filipino civilian deaths during the 15 years of US occupation range between 250,000 & 1,000,000 with the higher number accounting for those killed by war, malnutrition, & a cholera epidemic after the war.