[3] After graduating from college in 1933, Key relocated to New York City, where he published cartoons and illustrations in a number of periodicals, including Better Homes and Gardens, Collier's, The New Yorker, Ladies' Home Journal, Good Housekeeping, McCall's, Cosmopolitan, TV Guide, Mademoiselle, Look, and Judge.

[4] With the increased output of six cartoons a week, Key hired veteran gag cartoonist Stan Fine to lend a hand.

Key later adapted his comic panel into the television show Hazel, starring Shirley Booth as the titular maid.

[2] Key's other work in the comics field includes Diz and Liz, a two-page feature that ran in Jack and Jill magazine from 1961 to 1972, as well as conceiving and creating Peabody's Improbable History, the original Peabody segment for producer Jay Ward's animated television series The Rocky and Bullwinkle Show.

[6] Key also provided illustrations for the long-running "Positive Attitude" series of motivational pamphlets and posters, published biweekly by Economics Press Inc. from the 1960s to the 1980s.

[8] During World War II, Key served with the U.S. Army from 1943 to 1946, primarily in public relations, where he wrote a play aimed at recruiting women into military service.