One of the important elements in the novel is the Vietnam War, which took place fifteen years before the events in the book. The Vietnam War was a war that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975.
Where Benny Quintero, Duncan Oaks, and Mark Bethel came together was in Ia Drang. The Battle of Ia Drang comprises two main engagements conducted by the 1st Battalion, 7th Cavalry Regiment that took place on November 14–15, 1965 and by the 2nd Battalion, 7th Cavalry Regiment on November 17 at LZ Albany farther north in the Ia Drang Valley. It was the first major battle between the United States Army and the North Vietnamese Army-NVA during the Vietnam War.
One of the objects that Kinsey finds which belonged to Duncan Oaks is his dog tags. “Dog tags” is an informal but common term for the identification tags worn by military personnel. The tags are primarily used for the identification of dead and wounded soldiers; they have personal information about the soldiers and convey essential basic medical information, such as blood type and history of inoculations.
The city where Duncan, Benny, Mark, Laddie, and Duffy come from is Louisville in Kentucky. Louisville is the largest city in the Commonwealth of Kentucky and the 30th-most populous city in the United States.