One literary element that has historical relevance is the setting. The Color Purple takes place in rural Georgia, the deep South, and spans the years from approximately 1900-1940. The setting is important for several reasons. First, Georgia is a southern state, which was rife with racism against the African-Americans that lived there. This comes to light clearly in the scene where Sophia hits the Mayor's wife as well as the scene in which Celie and Corrine are in the store and the clerk speaks very rudely to them.
Secondly, the time period is important because this all takes place before the Civil Rights movement at a time when African Americans are subjected to Jim Crow Laws.