Shiloh is set in Western Kentucky during the early 1980s. It depicts many of the changes that rocked the region during the Reagan era, with expanding poverty, fewer economic oppurtunities, and rises in social problems including drug use, alcoholism, and crime. On the other hand, the period also saw more women (like Norma Jean) leaving their husbands and joining the workforce. Perhaps the predominant theme in the book is Norma Jean attempting to adapt to these changes rather than watching her life go by. Leroy, on disability from his job as a truck driver, is quite the opposite, and the two grow apart, as evidenced by this quotation:
Now Leroy has the sudden impulse to tell Norma Jean about himself, as if he had just met her. They have known each other so long that they have forgotten a lot about each other. They could become reacquainted. But when the oven timer goes off and she runs to the kitchen, he forgets why he wants to do this.