 He had conceived of the series while in Europe, imagining an Americana regional series in which regionalists would "describe and interpret the indigenous quality of life".His proposal was rejected by editors Marshall Best and Harold Guinzburg at Viking, but accepted by Charles Duell and Samuel Sloan as a foundational series of their new press, and as an opportunity for their press to acquire Caldwell's future works.In 1939 he began traversing the country, soliciting authors for the series, and by the end of the year had elicited commitments from five writers.