The book tells the story of the Battle of Gettysburg, attempting to present both a factual retelling of events as well as the emotional experience of living it. The book introduces the armies and individuals, the events leading up to the battle, and the action on a day-by-day, moment-by-moment basis. Using scenes that show the interactions of some of the men involved, you see the problems faced and decisions made, as well as the personal and individual reactions to those decisions. Aside from these surface things, the book also conveys the reality of war, with its losses and tragedies, and the motivations and deep emotions of the men there
The book starts with a Foreword that gives details of the armies and people involved. Four main chronological sections cover the days of Monday, June 29, 1863, through Friday, July 3, 1863, with the text alternating between the viewpoints of various Union and Confederate participants. An Afterword tells the reader what happens to several of the key characters. With the exception of the Foreword, which is written in the present tense, the entire book is written in the third person, past tense.
Each chapter within a section is from a different person's viewpoint, though the overall viewpoint of the novel is omniscient. Even though a chapter is written from one commander's perspective, the author still allows you to see what some of the other characters in those scenes are thinking. Also, you are able to watch that particular commander from outside himself as a spectator would.
The omniscient viewpoint gives the author a way to communicate many details, something that would be difficult to do through the eyes of only one person. This approach also allows for a broader perspective to the whole story because you see it through the eyes of so many people. The changing viewpoints and locations make it an active structure, which serves to intensify the emotions of the reader.
Shaara selects four main people as the viewpoint characters and moves back and forth among them to progress the story. This approach builds tension and allows personal connections to be made with the characters. Their backgrounds, desires, beliefs, and fears are revealed, and you see how these things, set against the canvas of events, will affect decisions and actions in the story.
On the Confederate side he focuses on Lee and Longstreet, while on the Union side he focuses on Buford and Chamberlain. He adds a couple of additional viewpoints to round out the story, using the characters of Harrison, a Confederate spy, Armistead, one of the Confederate commanders under Pickett, and Fremantle, an English observer on the Confederate side.
The viewpoint characters selected have significance for a few reasons. First, they give the reader a view of the action from the different levels of command. Secondly, they let you see the battle from two different locations: the sidelines and the action. Shaara's alternating of character viewpoints and locations provides glimpses of the planning, reasoning, and strategy sessions, as well as the in-the-moment battle experiences.