Twentieth century California Indians have received muted attention from scholars. The sheer size and diversity of California Indians can be overwhelming. Geographically, California is the third largest state and home to one hundred and ten federally recognized tribes. California Indians created alliances across the state among diverse tribal groups. Indian advocacy and activism of the twentieth century has been a limited discussion focused on four major events: Alcatraz occupation of 1969; Trail of Broken Treaties and subsequent occupation of the Bureau of Indian Affairs building of 1972; Wounded Knee of 1973; and the "Longest Walk" in 1978. These four major developments should not be ignored. However, the discussion should be broader and include diverse forms of advocacy and activism. In 1964 Rupert Costo, Cahuilla, his wife Jeannette Henry-Costo, Eastern Cherokee, and thirteen Indians from diverse tribes, largely from California, founded the American Indian Historical Society (AIHS). Costo served as president of the organization until its dissolution in 1986. The San Francisco based group sought to improve education, communication, and cultural development among Indians. Members of this activist organization challenged textbooks, testified at congressional hearings, created an Indian controlled publishing house, coordinated community meetings, and lobbied for protection of burial grounds. It also circulated, Wassaja, one of the first national Indian newspapers with original content. Through its publications, the AIHS sought to inform and promote mutual understanding between Indians and non-Indians. The AIHS' philosophy centered on the belief that Indians could, through their own initiative and innovation, lead the fight in Indian affairs. Through the years, the AIHS supported Indian issues and efforts of individual tribes to preserve their rights. Thus, the AIHS defended tribal self-determination and rejected pan-indianism. The federal government policy of relocation encouraged non-California Indians to move into California. Relocation caused friction as the focus by many in the mainstream media turned its attention to relocated Indians which increasingly rendered California Indians invisible. However, with conscientious effort the AIHS worked towards informing and educating Indians and non-Indians.

There exists a significant overlap between American Indian history and American history, yet historians often treat the two separately. The intersection has grown over time, increasingly so in the 20th and 21st centuries. Over time a process of syncretism has taken place wherein American Indians have been able to take their tribal histories and heritage and merge them with the elements of the dominant culture as they see fit. Many American Indians have found that they are able to use their cultural heritage to educate others using mainstream methods. Brummett Echohawk, a Pawnee Indian from Pawnee, Oklahoma demonstrated the ways in which American Indian history merged with the larger American historical narrative through his knowledge of Pawnee history and heritage, American history, and his active participation in mainstream society throughout the 20th and into the 21st century. As a student in a government run Indian boarding school, a soldier of the famed 45th "Thunderbird" Infantry Division in World War II, and a successful artist, writer and public speaker, he offered a view of how one could employ syncretism to the advantage of all. Using an ethnohistorical approach to the subject allows a consideration of Brummett Echohawk as an individual, a representative of the Pawnee people, American Indians generally, and as an American. The ethnohistorical approach also helps elucidate the connection he made between success in life and truly fulfilling the Pawnee meaning behind their name Chaticks-si-chaticks, Men of men. Personal papers, published writings, as well as published and privately owned art (ranging from fine art in prestigious galleries to comic strips) provide insight as to how Echohawk made clear the connections between the Pawnee (and American Indian) past and American history. Interviews with family members, friends, and Pawnee veterans also demonstrate the significance of his life for the Pawnee people and the United States, particularly in terms of the martial tradition.