Kerr Eby was born in 1890 in Tokyo, Japan, the son of Methodist missionaries from Canada. Returning to that country when he was three, Eby grew up studying art, which his parents encouraged, as his mother came from a family of prominent artists. As a boy he worked as a printer's apprentice in a newspaper office, which may have encouraged his interest in printing as an artistic medium.
After graduating from high school in 1907, Eby moved to New York City to study art, first at the Pratt Institute, and later at the Art Students League. During this period he formed a number of influential friendships with major artists such as John Henry Twachtman and Childe Hassam and joined a summer artists' colony founded by them at Cos Cob, Connecticut. He supported himself by working as a magazine illustrator and at the American Lithographic Company. Through study and practice, Eby refined both his drawing and printing techniques.
In 1917, when the United States entered World War I, Eby joined the U.S. Army. He tried to obtain a commission as an artist, but was assigned first to ambulance duty and later as a camoufleur to the 40th Engineers in France. During the war he documented in drawing what he saw and experienced and on his return to New York City, he translated his studies into prints. These works are powerful, reflecting his horror and disillusionment he felt. It was a subject that never left him. He continued creating out occasional war-related prints throughout the 1920's and 30's.
With another conflict beginning in the mid-1930's Eby wanted to show the world what war was really like. He pulled together works from his experience into a book entitled War. Though not strictly a pacifist, he wanted people to understand the horrible powers that could be unleashed. He believed that the cost of war should be understood, though it may be considered necessary.
When the United States declared war in 1941, Eby tried to enlist, but was turned down because of his age. He instead received his opportunity to participate when Abbott Laboratories developed its combat artist program. Between October 1943 and January 1944, he traveled with Marines in the South Pacific and witnessed some of the fiercest fighting of the war, landing with the invasion force at Tarawa and living three weeks in a foxhole on Bougainville. While on Bougainville he became ill with a tropical disease, one which weakened his health. He returned to the United States unable to regain his full strength. He completed his final drawings for Abbott and two unrelated etchings, but could not complete the etchings that he intended to make from his war pictures. He died in Norwalk, Connecticut in 1946.