1610 - 1622 - Deliberate genocide of Powhatans by London Virginia Company. It involved the manipulation of English Law by Sir Edward Coke a prominent jurist whose writings on the English common law were the definitive legal texts for some 300 years. There were two Anglo-Powhatan Wars accompanied by racist polemics preached by associates of the Company in London.
May 26, 1637 - English troops attacked a large Pequot village on the Mystic River in what is now Connecticut. The village was set on fire and the women and children were killed as they attempted to flee. One observer later wrote: "it was a fearful sight to see them thus frying in the fire and the steams of blood quenching the same, and horrible was the stink and scent thereof," William Bradford, Of Plymouth Plantation, page 296. In this and the succeeding campaign about 700 members of the tribe were killed including men taken captive. The tribe was disbanded and the survivors adopted by neighboring tribes.
1777 - deliberate devastation of Six Nations as British allies (estimated killed?)
April 22, 1818 - Chehaw Affair - 7 men killed (estimates from 7-40 killed), American troops attack friendly Indian village during First Seminole War
1832 - Black Hawk War - 850 men, women, children killed in war many at Bad Ax Massacre, Bad Ax Wisconsin by American militia and Indian allies
1838-1839 - Trail of Tears - 4,000 Cherokees, mainly died from disease and exposure during forced relocation. (see Indian Removal)
March 3, 1860 - Eureka, California - 80-100 men, women, children, Wiyot tribe killed by local hooligans
January 29, 1863 - Bear River Massacre - fewer than 250 killed
April 24, 1863 - Keyesville Massacre - Keyesville, California - 53 military age men, Tehachapi tribe
November 29, 1864 - Sand Creek Massacre - Sand Creek, Colorado - 150 men, women, and children killed, Cheyenne Indians
November 27, 1868 - Washita Massacre - Washita River, Oklahoma - 100 people killed; this is often considered a battle, not a massacre
January 23, 1870 - Marias Massacre - 200 Piegans, mainly elderly, women, and children
December 29, 1890 - Wounded Knee Massacre - Wounded Knee, South Dakota - 300 (est.) people killed.