McKimson left the studio during World War II to serve in the US Army Signal Corps, returning in 1946. Upon his return he was assigned to his brother Robert's unit, where he worked as a lead animator. Charles received co-story credit on one short, 1955's All Fowled Up (the other writer being Sid Marcus), starring Foghorn Leghorn — a character utilized exclusively by Robert.
During World War II, McKimson left the studio to serve in the US Army Signal Corps and returned in 1946. He was then assigned to his brother Robert's unit where he worked as a lead animator. Charles received co-story credit on one short film from 1955 titled "All Fowled Up," which starred Foghorn Leghorn — a character used exclusively by Robert.