These were complex nomadic cultures based on (introduced) horse culture and seasonal bison hunting. Cultural activism since the late 1960s has increased political participation and led to an expansion of efforts to teach and preserve indigenous languages for younger generations and to establish a greater cultural infrastructure: Native Americans have founded independent newspapers and online media, recently including First Nations Experience, the first Native American television channel; established Native American studies programs, tribal schools and universities, and museums and language programs; and have increasingly been published as authors.They carried out resistance against United States incursion in the decades after the end of the Civil War and the completion of the Transcontinental Railroad in a series of Indian Wars, which were frequent up until the 1890s but continued into the 20th century. agents encouraged Native Americans to adopt European-style farming and similar pursuits, but European-American agricultural technology of the time was inadequate for often dry reservation lands, leading to mass starvation. The terms used to refer to Native Americans have at times been controversial.Since the end of the 15th century, the migration of Europeans to the Americas has led to centuries of population, cultural, and agricultural transfer and adjustment between Old and New World societies, a process known as the Columbian exchange.Most Native American groups had historically preserved their histories by oral traditions and artwork, which has resulted in the first written sources on the conflict being authored by Europeans.The archaeological periods used are the classifications of archaeological periods and cultures established in Gordon Willey and Philip Phillips' 1958 book Method and Theory in American Archaeology.
Genetic evidence suggests at least three waves of migrants arrived from Asia, with the first occurring at least 15 thousand years ago.
While technically referring to the era before Christopher Columbus' voyages of 1492 to 1504, in practice the term usually includes the history of American indigenous cultures until they were conquered or significantly influenced by Europeans, even if this happened decades or even centuries after Columbus' initial landing.
Native American cultures are not normally included in characterizations of advanced stone age cultures as "Neolithic," which is a category that more often includes only the cultures in Eurasia, Africa, and other regions.
Expansion of European-American populations to the west after the American Revolution resulted in increasing pressure on Native American lands, warfare between the groups, and rising tensions. This resulted in the ethnic cleansing of many tribes, with the brutal, forced marches coming to be known as The Trail of Tears.
As American expansion reached into the West, settler and miner migrants came into increasing conflict with the Great Basin, Great Plains, and other Western tribes. Contemporary Native Americans have a unique relationship with the United States because they may be members of nations, tribes, or bands with sovereignty and treaty rights.