Given his own education and career, he favored children learning more about mainstream American culture. Writing In 1902, Eastman published a memoir, Indian Boyhood, recounting his first fifteen years of life among the Dakota Sioux during the later years of the nineteenth century. In the following two decades, he wrote ten more books, most concerned with his Native American culture. In the early 20th century, he was "one of the most prolific authors and speakers on Sioux ethnohistory and American Indian affairs." He also became one of the most photographed Native Americans, sometimes appearing his traditional Sioux regalia and sometimes in Euro-American clothing. Historians debate how Eastman and his wife worked together through the decades of his publishing career. Theodore Sargent, a biographer of Elaine, noted that Eastman gained acclaim for the nine books he published on Sioux life, whereas Elaine's seven books received little notice. According to Ruth Ann Alexander, Elaine is not given enough credit for his success, although she worked intensively on Charles's stories as a way both to share his life and to use her own literary talent as his typist and editor. Carol Lea Clark believes that the books under Eastman's name should be seen as a collaboration: "Together they produced works of a public popularity that neither could produce separately." After the couple separated in 1921, Eastman never published another book. These views, however, are contested by other Eastman scholars, who suggest they reflect a bias toward a European-American influence in Eastman's published works. Some Native scholars suggest that in fact, there is both content and style in Eastman's writing that reflects Indigenous techniques. While Elaine may have helped Eastman edit his work, Ruth J. Heflin argues that Elaine's later claims that she wrote his works ring false. She did not make that claim until after Eastman's death. It is likely, however, that Elaine was her husband's typist; Eastman apparently did not learn to type. He was reported to have lost his government position because he could not type his required reports. Other scholars debate the influence and role Elaine might have played in shaping Charles’ prose. Some of Eastman's books were translated into French, German, Czech and other European languages. They sold well enough to undergo regular reprints. In the early 21st century, a selection of his writings was published as The Essential Charles Eastman (Ohiyesa) (2007). Youth organizations Inspired by his writings,