Philippine-American War
AD – MPE: 0.27
The Wikipedia-article called “Philippine-American War” cites estimates for the number of civilians killed from 1899 to 1902, which range from 0.2 to 1 million. If all victims of epidemics and malnutrition are included, plausible estimates for excess deaths go up to 0.8 million. It is difficult to estimate how many of these civilians fell victim to criminal policies. Rummel estimates 0.13 democides by the US. The US interned large numbers of Filipinos in camps with high mortality rates. They also burned down entire villages.
Plausible estimates for the number of civilians killed by the US range from 0.1 to 0.6 million. I choose 0.27 million as the most plausible estimate.