The Historical Journal of Massachusetts has an informative article on King Philip’s War. The 1675 – 1676 conflict was the bloodiest in American history, when population is taken into account. From the abstract:

Recent scholarship has underscored the carnage inflicted by King Philip’s War (1675-76). Colonists faced a diverse assortment of Native Americans led by Wampanoag sachem Metacom (whom the colonists referred to as King Philip). In terms of population, King Philip’s War was the bloodiest conflict in American history. Fiftytwo English towns were attacked, a dozen were destroyed, and more than 2,500 colonists died – perhaps 30% of the English population of New England. At least twice as many Native Americans were killed. Some historians estimate that the combined effects of war, disease, and starvation killed half the Native population of the region. The war left an enduring legacy.