THE OTHER KILLER
While the battles left huge numbers of wounded and dead in short periods of time, long-term the soldiers were much more likely to die of disease. Among Federal forces, approximately 3 out of 5 died of disease, and among Confederates, perhaps 2 out of 3.
Half of the deaths from disease were caused by intestinal disorders, mainly diarrhea, dysentery, and typhoid fever. The rest died primarily of pneumonia and tuberculosis.
Camps were plagued with outbreaks of measles, chickenpox, mumps, and whooping cough. The Union army reported that more than 995 out of every 1,000 men eventually contracted chronic diarrhea or dysentery during the war; the Confederates fared no better.
Typhoid fever was even more devastating. Perhaps one-quarter of noncombat deaths in the Confederacy resulted from this disease, caused by the consumption of food or water contaminated by salmonella bacteria.
Epidemics of malaria spread through camps located next to stagnant swamps teeming with anopheles mosquito. Although treatment with quinine reduced fatalities, malaria nevertheless struck approximately one quarter of all servicemen; the Union army alone reported one million cases of it during the course of the war.
Poor diet and exposure to the elements only added to the burden. A simple cold often developed into pneumonia, which was the third leading killer disease of the war, after typhoid and dysentery.
(Source: The Civil War Society's "Encyclopedia of the Civil War") | 
