New recruits were sent to large camps to learn how to become soldiers. The first enemy they faced was disease. Healthy recruits became victims of illnesses that were easily spread due to the large number of people in the camps, the often unsanitary conditions, and the poor diet of the soldiers. Childhood diseases such as measles could devastate regiments and many men succumbed to diarrhea and dysentery. Of the nearly 620,000 soldiers who died during the Civil War, two-thirds died not of bullets and bayonets, but of disease.