East of Eden is set in the United States following the American Civil War. It documents the lives of multiple individuals and families, all of whom spend their lives in different parts of the continental United States, from the West to the East Coast. California, specifically the Salinas Valley, is a key location in East of Eden, both for its narrative significance and its relevance to Steinbeck himself. The author himself called Salinas home and set many of his stories in the surrounding agricultural valleys.
As an allegorical retelling of the book of Genesis, East of Eden defines California as the titular Garden of Eden before humanity's fall—specifically, Salinas, where Adam buys land and settles. The California/Eden comparison is an apt one, given the state's unique role in the American creation myth. During the period of rapid westward colonial expansion and settlement that took place over the course of the 19th and early 20th century, California was commonly depicted as the land of plenty: gold miners, farmers, and oil prospectors all headed to the state to seek their fortune. In the American colonial imagination, California was a kind of Eden—the perfect manifestation of American destiny. In a book that retells and recontextualizes the Biblical myth of creation, California is the perfect setting.