Southern literature varies widely in its themes depending upon the historical period in which it is written.  The old Southern themes of religion, primarily Christianity, along with the themes of slavery and racial tensions, are usually quite specific in this region.  

To better understand the differing themes and characteristics in southern literature, we need to recognize the wide berth of development that the southern United States has experienced. The Southerners were not of Puritanical roots, but more of a melting pot of cultures that sought a clean slate where they could live a new life separate from the Northeast. This relied heavily on religion, an agrarian lifestyle, and a sense of purity in nature. As time marched on, the antebellum Southerners were viewed negatively by their Yankee counterparts. They were characterized as lazy, ill-educated, and cruel, as the South's dependence upon slavery grew. There is also the opposing theme from writers such as Frederick Douglas and those authors of the slave narratives.

The Plantation novel also came into style some time after the Civil War. These writings contained an almost sorrowful wistfulness for the life of the old plantations, now diminishing after the Southern loss. 

Then comes the Southern Renaissance, where you have prolific writers such as Alice Walker, Eudora Welty, Carson McCullers, and Flannery O'Connor. These and many other writers, such as Mark Twain and William Faulkner, write about similar thematic ideas as the earlier writers, although there is a definite shift. This shift can be categorized as a focus on the individual versus society as a whole, such as in The Heart is a Lonely Hunter by Carson McCullers. Here you have highly idiosyncratic characters trying to survive in a world oftentimes against the odds. There is still a pervasive sense of religious importance in Southern life, although sometimes this is made perverse in stories such as "A Good Man is Hard to Find," or "Everything That Rises Must Converge." 

Southern literature is as varied and flavorful as the people who inhabit its regions, from the bayous to the swamps, to the beautiful plantation settings and charm of the antebellum period. The themes of religion, family, rural life, and racial inequalities continue to run throughout Southern literature.