Martha Gellhorn stowed away on a hospital ship to become the only woman journalist to land on Normandy Beach on D-Day. She carried stretchers before writing her harrowing account of the invasion. The New Yorker’s famously epicurean writer A.J. Liebling subsisted on military rations and came under fire during World War II to describe what it was like for the soldiers and sailors at war. Syndicated columnist Ernie Pyle died, in a helmet and Army fatigues, among some of the troops whose names and hometowns he carefully included in his dispatches. “At this spot, the 77th Infantry lost a buddy,”...