The 1920s saw the end of the Federal Allotment policy, with its focus on forcing Indians to assimilate and become small farmers and landowners. A collosal failure by any reckoning, Allotment had led to a tremendous erosion of the Indian land base and to general impoverishment and population decline in Native communities. (The nadir of Indian population in the United States was in 1900, when about 375,000 Indians were living in the U.S., Canada, and Greenland). Full recognition of this failure came during the 1920s, but it was not until the passage of the Wheeler-Howard Act (the Indian Reorganization Act) in 1934 that policy change followed suit. At that point, under the John Collier-led BIA, we can trace a concerted attempt to better recognize and respect tribal cultural practices (and, to a lesser degree, political sovereignty).
The New Deal emphasis on undoing at least some of the damage of the assimilationist policies of the preceeding decades was reflected in the autobiographical writing of the time. The 1920s saw the beginning of the real rise of ethnographic autobiography, "as-told-to" accounts taken down by anthropologists and folklorists as a way of preserving traditions in danger of being lost. (Such texts, produced using increasingly sophisticated methodologies, continue to be an important part of the autobiographical canon.) Admittedly, much of the "salvage ethnography" of the early to mid 20th century was infused with a pernicious fatalism, one based on assumptions regarding the "inevitable" decline of Indian culture in the wake of modernity. Often, though, non-Indian editors collected and presented their material as a way of commenting critically on moderninty. Quite frequently, as in the case of John G. Neihardt's Black Elk Speaks, we find a bit of both.
The desire to record (and often to valorize) Indian life also appears behind the most famous, independently written texts of the time as well. Relatively speaking, though, the most well-known texts of this period are collaborative offerings, written with an ethnographic emphasis. In this respect, it is fair to suggest that the greater political openness to traditional Indian lifeways during the New Deal era deeply informs the literary work of that time. Arguably, the autobiographies produced during this period of openness (interrupted by the ill-conceived Termination policy of the 1950s) also provided the foundation for the explosion of innovative work during the so-called Native American Renaissance of the 1960s.