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.

Military service and urban residency contributed to the rise of American Indian activism, particularly after the 1960s and the occupation of Alcatraz Island (1969-1971) by a student Indian group from San Francisco. In the same period, the American Indian Movement (AIM) was founded in Minneapolis, and chapters were established throughout the country, where American Indians combined spiritual and political activism. Political protests gained national media attention and the sympathy of the American public.  Through the mid-1970s, conflicts between governments and Native Americans occasionally erupted into violence. A notable late 20th-century event was the Wounded Knee incident on the Pine Ridge Indian Reservation. Upset with tribal government and the failures of the federal government to enforce treaty rights, about 300 Oglala Lakota and AIM activists took control of Wounded Knee on February 27, 1973.  Indian activists from around the country joined them at Pine Ridge, and the occupation became a symbol of rising American Indian identity and power. Federal law enforcement officials and the national guard cordoned off the town, and the two sides had a standoff for 71 days. During much gunfire, one United States Marshal was wounded and paralyzed. In late April, a Cherokee and local Lakota man were killed by gunfire; the Lakota elders ended the occupation to ensure no more lives were lost.  In June 1975, two FBI agents seeking to make an armed robbery arrest at Pine Ridge Reservation were wounded in a firefight, and killed at close range. The AIM activist Leonard Peltier was sentenced in 1976 to two consecutive terms of life in prison in the FBI deaths.  In 1968, the government enacted the Indian Civil Rights Act. This gave tribal members most of the protections against abuses by tribal governments that the Bill of Rights accords to all U.S. citizens with respect to the federal government. In 1975, the U.S. government passed the Indian Self-Determination and Education Assistance Act, marking the culmination of fifteen years of policy changes. It resulted from American Indian activism, the Civil Rights Movement, and community development aspects of President Lyndon Johnson's social programs of the 1960s. The Act recognized the right and need of Native Americans for self-determination. It marked the U.S. government's turn away from the 1950s policy of termination of the relationship between tribes and the government. The U.S. government encouraged Native Americans' efforts at self-government and determining their futures. Tribes have developed organizations to administer their own social, welfare and housing programs, for instance. Tribal self-determination has created tension with respect to the federal government's historic trust obligation to care for Indians; however, the Bureau of Indian Affairs has never lived up to that responsibility.

What did that entail?
This gave tribal members most of the protections against abuses by tribal governments that the Bill of Rights accords to all U.S. citizens