“...As the war came to an end in the north, suddenly the south island of Mindanao erupted with the first battle taking place between the Americans and the Muslim Moros on May 2, 1902; the Battle of Bayan. Yes, they were Muslim and the fieriest warriors of all. The Americans killed about half of the 600 Moros warriors. About 10% of the American troops were severely wounded in a matter of minutes. American troops ran out of ammo and fixed their bayonets. A wave of Moro warriors were hiding in nearby trenches and charged, swinging their terrifying bolo short swords and some with the double-handled kampilan, while others had the double-edged wavy kris that was considered to be the most deadly of all. One survivor of that battle, Capt. C.C. Smith, recounted that “in hand-to-hand combat our soldiers are no match for the Moro. If our first shot misses the target, we rarely have time to get off another.” In the end, all the officers were killed and about half of the American troops were cut down. Only a torrential rainfall saved the rest....”
It was not the island of Mindanao that “erupted”, it was specific parts of it, that were Muslim in the first place, for various reasons, and at various times, over a dozen years.
Certainly not all at once, or indeed not all of it in any case. It was this tribe, that chief, that river valley. US columns marched up the Cotabato river or Lake Lanao, taking the submission of each kotah, or besieging it, as seemed appropriate. The islands of Jolo (another ancestor was on the Spanish expedition that too that perpetual sore thumb) was a frequent trouble spot.
Even the Americans running these campaigns thought they were much like the Indian wars.