The American Indian Wars (also called American Frontier Wars, & the First Nations Wars) were fought by European governments seeking economic expansion into the Americas & by their colonists, & later by the newly formed United States & Canadian governments plus their settlers, against various American Indian & First Nation tribes.
America's native people prior to the European invasion were a complex mixture of histories, alliances & conflicts. Humans are human, & some native tribes acted towards one another with the same brutality as the Europeans did towards them, & visa versa. Grudges & the lure of power were similar. It is believed that the colonists intentionally spread contagious diseases among the natives, usually through gifts of infected blankets or clothing. Measles & smallpox probably killed more natives than bullets & bayonets. The Native's "stone age" war technologies eventually succumbed to the deceptions & weapons of the Europeans.
These particular conflicts occurred in North America from the time of the earliest European colonial settlements from the 17C until the early 20C. The various wars resulted from a wide variety of factors. These wars usually resulted in the sovereignty of combatants being either extended or lost; a massive native indigenous population decline; deportation & forced assimilation of indigenous tribes; many treaties, truces, & armistices made & then broken by combatants; & the establishment of "Indian reservations" in the United States & Canada.
The European political & economic powers & their colonies also enlisted allied Indian tribes to help them conduct warfare against each other's colonial settlements.
After the American Revolution, many conflicts were local to specific states or regions & frequently involved disputes over land use; some entailed repeated cycles of violent reprisal.
As settlers spread westward across North America after 1780, armed conflicts increased in size, duration, & intensity between the European settlers & various Native & First Nation tribes. The climax came in the War of 1812, when major Indian coalitions in the Midwest & the South fought against the United States & lost. Conflict with settlers became less common & was usually resolved by treaty, often involving sale or exchange of territory between the federal government & specific tribes.
The Indian Removal Act of 1830 authorized the American government to enforce Native American removal from east of the Mississippi River to Indian Territory west on the American frontier, such as the land that later became Oklahoma. The federal policy of removal was eventually refined in the West, as American settlers kept expanding their territories, to relocate native tribes to restricted land areas called reservations.
See:
Barnes, Jeff. Forts of the Northern Plains: Guide to Historic Military Posts of the Plains Indian Wars. Mechanicsburg, Pennsylvania: Stackpole Books, 2008.
Glassley, Ray Hoard. Indian Wars of the Pacific Northwest, Binfords & Mort, Portland, Oregon 1972
Heard, J. Norman. Handbook of the American Frontier (Compilation of Indian-white contacts & conflicts) Scarecrow Press, 1987–98
Volume 1: "The Southeastern Woodlands,"
Volume 2: "The Northeastern Woodlands,"
Volume 3: "The Great Plains,"
Volume 4: "The Far West,"
Volume 5: "Chronology, Bibliography, Index."
Kessel, William and Robert Wooster. Encyclopedia of Native American Wars and Warfare (2005)
McDermott, John D. A Guide to the Indian Wars of the West. Lincoln: University of Nebraska Press, 1998.
Merrell, James H (1989). "Some Thoughts on Colonial Historians & American Indians" William and Mary Quarterly. 46
Merrell, James H (2012). "Second Thoughts on Colonial Historians & American Indians" William and Mary Quarterly. 69
Michno, Gregory F. Deadliest Indian War in the West: The Snake Conflict, 1864–1868, Caxton Press, 2007
Miller, Lester L, Jr. Indian Wars: A Bibliography US Army, 1988 online (lists over 200 books & articles)
Stannard, David. American Holocaust: Columbus and the Conquest of the New World, Oxford, 1992
Tucker, Spencer, ed. The Encyclopedia of North American Indian Wars, 1607–1890: A Political, Social, and Military History (3 vol 2012)
Wooster, Robert. The Military and United States Indian Policy, 1865–1903, Published 1995