Disney as an ambulance driver during World War I.In 1917, Elias acquired shares in the O-Zell jelly factory in Chicago and moved his family back there.[13] In the fall, Disney began his freshman year at McKinley High School and began taking night courses at the Chicago Art Institute.[14] Disney became the cartoonist for the school newspaper. His cartoons were very patriotic, focusing on World War I. Disney dropped out of high school at the age of sixteen to join the Army, but the army rejected him because he was underage.[15]

After his rejection from the army, Walt and one of his friends decided to join the Red Cross.[16] Soon after he joined The Red Cross, Walt was sent to France for a year, where he drove an ambulance.[17]

In 1919, Walt, hoping to find work outside the Chicago Ozell factory,[18] left home and moved back to Kansas City to begin his artistic career.[19] After considering becoming an actor or a newspaper artist, he decided he wanted to create a career in the newspaper, drawing political caricatures or comic strips. But when nobody wanted to hire him as either an artist or even as an ambulance driver, his brother Roy, who worked at a bank in the area, got a temporary job for him at the Pesmen-Rubin Art Studio through a bank colleague .[19] At Pesmen-Rubin, Disney created ads for newspapers, magazines, and movie theaters.[20] It was here that he met a cartoonist named Ubbe Iwerks.[21] When their time at the Pesmen-Rubin Art Studio expired, they were both without a job, and they decided to start their own commercial company.[22]

In January 1920, Disney and Iwerks formed a short-lived company called, "Iwerks-Disney Commercial Artists". However, following a rough start, Disney left temporarily to earn money at Kansas City Film Ad Company, and was soon joined by Iwerks who was not able to run the business alone.[23] While working for the Kansas City Film Ad Company, where he made commercials based on cutout animation, Disney took up an interest in the field of animation, and decided to become an animator.[24] He was allowed by the owner of the Ad Company, A.V. Cauger, to borrow a camera from work, which he could use to experiment with at home. After reading a book by Edwin G. Lutz, called Animated Cartoons: How They Are Made, Their Origin and Development, he found cel animation to be much more promising than the cutout animation he was doing for Cauger. Walt eventually decided to open his own animation business,[25] and recruited a fellow co-worker at the Kansas City Film Ad Company, Fred Harman, as his first employee.[25] Walt and Harman then secured a deal with local theater owner Frank L. Newman-arguably the most popular "showman" in the Kansas City area at the time-[26] to air their cartoons — which they titled "Laugh-O-Grams" — at his local theater.[26]