Al Capp veterans returning from the war. Capp was also involved with the Sister Kenny Foundation, which pioneered new treatments for polio in the 1940s. Serving in his capacity as honorary chairman, Capp made public appearances on its behalf for years, contributed free artwork for its annual fund-raising appeals, and entertained crippled and paraplegic children in children's hospitals with inspirational pep talks, humorous stories and sketches. In 1940, an RKO movie adaptation starred Granville Owen (later known as Jeff York) as Li'l Abner, with Buster Keaton taking the role of Lonesome Polecat, and featuring a title song with lyrics by Milton Berle.
Al Capp dealt with northern urban experiences until the year Capp introduced "Li'l Abner," the first strip based in the South. Although Capp was from Connecticut, he spent 43 years teaching the world about Dogpatch, reaching an estimated 60 million readers in over 900 American newspapers and 100 foreign papers in 28 countries. M. Thomas Inge says Capp made a large personal fortune on the strip and "had a profound influence on the way the world viewed the American South". Born in New Haven, Connecticut, of East European Jewish heritage, Capp was the eldest child of Otto Philip and Matilda (Davidson) Caplin.