It was World War II when Sgt. George Baker created The Sad Sack, an unnamed inept Army private who invariably experienced the follies of military life. The Sad Sack first appeared in Yank, The Army Weekly #1 in June 1942. Two collections of the popular comic strip were published by Simon and Schuster (1944 and 1946); the first collection also appeared as an Armed Services paperback. After the war, Baker took the hapless soldier into newspaper syndication from 1946 to 1958, when he sold the rights to Harvey Comics, which in turn published 268 issues of the comic, plus a one-shot issue in which The Sad Sack goes home, as well as eleven spin-off series which brought the number of Sad Sack comics to about 600 issues through 1982.
Private Sad Sack also hit the radio, voiced by Mel Blanc, in various episodes of G.I. Journal, beginning in 1944. The Sad Sack also ran as a summer replacement program for The Frank Sinatra Show in 1946; this time the character was voiced by Herb Vigran. Jerry Lewis took the character to the wide screen in 1957. this time giving him the name of Meredith C. Bixby. The film also starred Phyllis Kirk, David Wayne, Peter Lorre, and and Joe Mantell.
Here's Mel Blanc as The Sad Sack from the April 29, 1944 episode of G.I. Journal.