This chapter recounts what is known of Holmes’s experiences during the Civil War. From the slaughter at Balls Bluff, to the struggles on the Peninsula, through Fredericksburg I and II, Antietam, Gettysburg and the Wilderness, his regiment encountered the worst that war could offer. Holmes himself was wounded three times and suffered a nearly fatal bout of dysentery. Each wound returned him to Boston to his family’s care, and each time he went back to face more of what he came to think was butchery. The chapter also tries to sort out the confusion over why Holmes left the army at the end of his enlistment.