Answer by taking a quote from the following article:

Native Americans, also known as American Indians, Indians, Indigenous Americans and other terms, are the indigenous peoples of the United States. There are over 500 federally recognized tribes within the U.S., about half of which are associated with Indian reservations. The term excludes Native Hawaiians and some Alaska Natives. The ancestors of modern Native Americans arrived in what is now the United States at least 15,000 years ago, possibly much earlier, from Asia via Beringia.

Iroquois Culture: The Iroquois League of Nations or "People of the Long House", based in present-day upstate and western New York, had a confederacy model from the mid-15th century. It has been suggested that their culture contributed to political thinking during the development of the later United States government. Their system of affiliation was a kind of federation, different from the strong, centralized European monarchies.Leadership was restricted to a group of 50 sachem chiefs, each representing one clan within a tribe. The Oneida and Mohawk people had nine seats each; the Onondagas held fourteen; the Cayuga had ten seats; and the Seneca had eight. Representation was not based on population numbers, as the Seneca tribe greatly outnumbered the others. When a sachem chief died, his successor was chosen by the senior woman of his tribe in consultation with other female members of the clan; property and hereditary leadership were passed matrilineally. Decisions were not made through voting but through consensus decision making, with each sachem chief holding theoretical veto power. The Onondaga were the "firekeepers", responsible for raising topics to be discussed. They occupied one side of a three-sided fire (the Mohawk and Seneca sat on one side of the fire, the Oneida and Cayuga sat on the third side.)  Elizabeth Tooker, an anthropologist, has said that it was unlikely the US founding fathers were inspired by the confederacy, as it bears little resemblance to the system of governance adopted in the United States. For example, it is based on inherited rather than elected leadership, selected by female members of the tribes, consensus decision-making regardless of population size of the tribes, and a single group capable of bringing matters before the legislative body.  Long-distance trading did not prevent warfare and displacement among the indigenous peoples, and their oral histories tell of numerous migrations to the historic territories where Europeans encountered them. The Iroquois invaded and attacked tribes in the Ohio River area of present-day Kentucky and claimed the hunting grounds. Historians have placed these events as occurring as early as the 13th century, or in the 17th century Beaver Wars.  Through warfare, the Iroquois drove several tribes to migrate west to what became known as their historically traditional lands west of the Mississippi River. Tribes originating in the Ohio Valley who moved west included the Osage, Kaw, Ponca and Omaha people. By the mid-17th century, they had resettled in their historical lands in present-day Kansas, Nebraska, Arkansas and Oklahoma. The Osage warred with Caddo-speaking Native Americans, displacing them in turn by the mid-18th century and dominating their new historical territories.  After the Indian wars in the late 19th century, the government established Native American boarding schools, initially run primarily by or affiliated with Christian missionaries. At this time, American society thought that Native American children needed to be acculturated to the general society. The boarding school experience was a total immersion in modern American society, but it could prove traumatic to children, who were forbidden to speak their native languages. They were taught Christianity and not allowed to practice their native religions, and in numerous other ways forced to abandon their Native American identities.  Before the 1930s, schools on the reservations provided no schooling beyond the sixth grade. To obtain more, boarding school was usually necessary. Small reservations with a few hundred people usually sent their children to nearby public schools. The "Indian New Deal" of the 1930s closed many of the boarding schools, and downplayed the assimilationist goals. The Indian Division of the Civilian Conservation Corps operated large-scale construction projects on the reservations, building thousands of new schools and community buildings. Under the leadership of John Collier the BIA brought in progressive educators to reshape Indian education. The Bureau of Indian Affairs (BIA) by 1938 taught 30,000 students in 377 boarding and day schools, or 40% of all Indian children in school. The Navajo largely opposed schooling of any sort, but the other tribes accepted the system. There were now high schools on larger reservations, educating not only teenagers but also an adult audience. There were no Indian facilities for higher education. They deemphasized textbooks, emphasized self-esteem, and started teaching Indian history. They promoted traditional arts and crafts of the sort that could be conducted on the reservations, such as making jewelry. The New Deal reformers met significant resistance from parents and teachers, and had mixed results. World War II brought younger Indians in contact with the broader society through military service and work in the munitions industries. The role of schooling was changed to focus on vocational education for jobs in urban America.  Since the rise of self-determination for Native Americans, they have generally emphasized education of their children at schools near where they live. In addition, many federally recognized tribes have taken over operations of such schools and added programs of language retention and revival to strengthen their cultures. Beginning in the 1970s, tribes have also founded colleges at their reservations, controlled, and operated by Native Americans, to educate their young for jobs as well as to pass on their cultures.  Some 44,000 Native Americans served in the United States military during World War II: at the time, one-third of all able-bodied Indian men from eighteen to fifty years of age. Described as the first large-scale exodus of indigenous peoples from the reservations since the removals of the 19th century, the men's service with the U.S. military in the international conflict was a turning point in Native American history. The overwhelming majority of Native Americans welcomed the opportunity to serve; they had a voluntary enlistment rate that was 40% higher than those drafted.  Their fellow soldiers often held them in high esteem, in part since the legend of the tough Native American warrior had become a part of the fabric of American historical legend. White servicemen sometimes showed a lighthearted respect toward Native American comrades by calling them "chief". The resulting increase in contact with the world outside of the reservation system brought profound changes to Native American culture. "The war", said the U.S. Indian Commissioner in 1945, "caused the greatest disruption of Native life since the beginning of the reservation era", affecting the habits, views, and economic well-being of tribal members. The most significant of these changes was the opportunity--as a result of wartime labor shortages--to find well-paying work in cities, and many people relocated to urban areas, particularly on the West Coast with the buildup of the defense industry.  There were also losses as a result of the war. For instance, a total of 1,200 Pueblo men served in World War II; only about half came home alive. In addition, many more Navajo served as code talkers for the military in the Pacific. The code they made, although cryptologically very simple, was never cracked by the Japanese.

How did the American's react to the Indians?
At this time, American society thought that Native American children needed to be acculturated to the general society.