“Hassler’s history [will survive] as our most detailed narrative of the first day’s battle, examining the day’s action so minutely that no succeeding historian of Gettysburg will be able to ignore it. Hassler’s book has solid virtues in addition to its thoroughness of detail: It offers a persuasive argument that the first day’s events largely determined the eventual outcome of the battle. Hassler displays uncommonly complete knowledge of the battlefield terrain . . . [and] makes uniquely good use of the information that can be gleaned from the monuments and markers on the battlefield.” 
—American Historical Review

“Hassler’s forte is unit combat; he combines a thorough mastery of the terrain with concise and colorful accounts of the ferocious fighting of that bloody day. His creation of the clash of brigades is Civil War history at its best.” 
—Civil War History

“Hassler, a noted Civil War authority, has concentrated on the terrible, crucial combat of the first day; students of the war will appreciate Hassler’s good research and writing. The book is a clear presentation of a complex battle. Highly recommended.” 
—CHOICE