Sickness, not combat, killed most Civil War soldiers. During the early months of the war, especially, disease ran rampant through both the U.S. and Confederate armies. Many men had never developed immunity to diseases such as mumps and measles. Cholera and typhoid fever spread through poor sanitation. Medical officials hastily set up hospitals. According to the patients who wrote this 1861 letter to Confederate President Jefferson Davis, however, conditions, treatments, and medical expertise were lacking.
National Archives, War Department Collection of Confederate Records