In the Shenandoah Valley and Peninsula Campaigns of 1862, Union and Confederate soldiers faced unfamiliar and harsh environmental conditions--strange terrain, tainted water, swarms of flies and mosquitoes, interminable rain and snow storms, and oppressive heat--which contributed to escalating disease and diminished morale. Using soldiers' letters, diaries, and memoirs, plus a wealth of additional personal accounts, medical sources, newspapers, and...