On September 3, 1923, Addison Morton Walker was born in El Dorado, a beginning that would eventually lead him to a long career working in American comics. He was educated at Metropolitan Community College and the University of Missouri before going on to work as a cartoonist, comics writer, and comics artist.

Walker's most notable work was Beetle Bailey, the comic strip that occupied much of his professional life. Written and drawn in English, the strip became the anchor of his public identity as a cartoonist. Over the course of his career, Walker accumulated a substantial record of recognition from within the industry, receiving the Reuben Award, the Inkpot Award, the Gold T-Square Award, and the Adamson Awards. Each of these honors came from organizations and events central to the world of cartooning and comics, placing Walker among those the field chose to acknowledge formally and repeatedly.

The Will Eisner Comic Industry Award Hall of Fame induction stood as one of the more significant markers of how Walker was regarded among his peers and successors. He continued working well into his later decades, a career sustained across an unusually long span of time. Walker died on January 27, 2018, in Stamford, at the age of ninety-four. The Library of Congress catalogs his work under the authorized label "Walker, Mort," a quiet but concrete measure of the archival weight his output accumulated over the course of his life in comics.