Lewis was born in
New Salem, Pennsylvania on October 12, 1858. He graduated 11th of 37 from the
United States Military Academy in 1884 and was commissioned as a second lieutenant in the Second Artillery. Early in his career he made himself an authority on
ordnance. In 1900, then-Captain Lewis was sent by Adjutant General
Henry Clarke Corbin to
Europe to study that subject, In 1911, he refined an original machine gun design of Samuel Maclean and began active marketing of a type which came to be known simply as the "Lewis Gun", which was used in
World War I by the Allied armies, the
United States Navy, and the airplanes of the United States and Allies. Initially, the United States Army was not interested in his new gun, but after the
British and
French had bought more than 100,000 for use in the trenches in France, the US Army did purchase them. Lewis, already a wealthy man, declined the
royalties—amounting to at least $1.2 million (equivalent to $ million in )—on guns made for the United States after it entered the war. His other inventions included a time-interval clock and bell system of signals, a replotting and relocating system for coast batteries, an automatic
sight, quick-reading mechanical
verniers for use in coast defenses, electric car lighting, and windmill electric lighting systems. He was awarded the
Franklin Institute's
Elliott Cresson Medal in 1919. ==Death and interment==