Diseases have devastated humankind before written records. They have killed and crippled more persons than all wars ever fought. The United States has been involved in Indian wars, international wars, the Civil War and two World Wars. This publication will illustrate military activity for 13 major U.S. wars. The major emphasis of this book is how diseases resulted in higher death loss than enemy action during these wars. As an example, two-thirds of Civil war deaths were from disease. During wars diseases became more severe due to the closeness of fighting troops.

Diseases causing the greatest deaths during wars included smallpox, typhoid fever, yellow fever, diarrhea/dysentery, typhus, malaria influenzas, pneumonia, and tuberculosis. Disease rates were reduced by World War II due to development of vaccines for disease prevention, improved sanitation, and better insect reduction (e.g., mosquitoes).