John Mitchell Vanderslice's Gettysburg offers an overarching history of the Battle of Gettysburg and describes the Gettysburg Battlefield Memorial Association's origins and accomplishments. The Memorial Association, established by an act of the Pennsylvania legislature in 1864, aimed to preserve and protect the battlefield grounds and gather information about the battle. It helped acquire land from private owners and oversaw the creation of monuments, avenues, and signs-laying the foundation for today's Gettysburg National Military Park.

This volume, published in 1897, provides a history of the Memorial Association as well as an overview of the battlefield, the armies, and the three days of battle at Gettysburg, including breakdowns of reported losses for each brigade on each part of the battlefield. Vanderslice also includes a history of the Gettysburg National Cemetery-the first national cemetery fully devoted to the burial of soldiers-with notes on its establishment, design, graves, organization, and dedication. The volume concludes with a detailed listing of each state's representation on the battlefield and memorial markers.