Richard Gatling gave this as the reason he invented the Gatling gun.
Reduce the size of armies
Shorten the Civil War
To make money
Give US a weapon equal to Europe’s
To reduce the size of armies. He wrote in 1877 that during the Civil War he saw that most deaths among soldiers came from sickness and exposure. By developing a rapid-fire weapon that would "enable one man to do as much battle duty as a hundred," he hoped to reduce the need for large armies and their attendant susceptibility to disease.