At least 10,000 soldiers were killed or mortally wounded in the three-day Battle of Gettysburg. More than 5,000 of these deaths were suffered by Union officers and enlisted men. Author Greg Coco mined the sources to pull out eyewitness accounts to illustrate the last moments, hours, or days of 100 Federals who fell there, all meticulously detailed and substantiated by historian Greg Coco.