Focusing on Indian religious ceremonies, she specifies the different spiritual needs of big game hunters, seed gatherers, and planters and details the ways these requirements are expressed in vastly different ceremonies and beliefs about birth, death, and the spirits.  The study concludes with a consideration of new religions evolved by the Indians after contact with the white man, including the Ghost Dance and the Peyote Religion

The late Ruth M. Underhill studied Indian history and customs for many decades, first as a student, then as an official of the Indian Bureau, as an anthropologist and as a writer and worker in Indian affairs.  Her Red Man's America, available in paperback from the University of Chicago Press, is widely known and highly regarded.