In 1945, after graduating from Venice High School and serving in the Army during World War II, Mr. Deitch was on the art staff in the sales promotion department at CBS when he sent some drawings to The Record Changer, a jazz publication.

The magazine published them, and more followed. (His Record Changer drawings were published in a book, “The Cat on a Hot Thin Groove,” in 2003.) There were jazz fans at UPA, and he ended up there as an apprentice designer.

Mr. Deitch worked on safety films for the military and some of the earliest Mr. Magoo cartoons. He moved to a Detroit studio for a time, but in 1951 UPA lured him back to help open its New York office. Among his biggest successes there was a series of animated commercials for the Brooklyn beer Piels, with Bob Elliott and Ray Goulding — the comedy team Bob & Ray — providing the voices.

“The beer was dreadful,” Mr. Deitch wrote, “but the commercials boosted its sales phenomenally.”

In 1956, CBS hired him to manage Terrytoons, a venerable cartoon studio it had just bought. His signature creation there, in 1957, was Tom Terrific, the hero of a serial cartoon broadcast as part of the children’s show “Captain Kangaroo.”

Mr. Deitch, though, found the atmosphere at Terrytoons hostile.

“After three years,” he wrote in his memoir, “For the Love of Prague” (1995), “I pulled the knife from my back, and in May 1958, I set up my own animation studio.”

A project on his wish list was to turn Mr. Feiffer’s story of the drafted 4-year-old into an animated film. He made a deal with William L. Snyder, a producer who had founded Rembrandt Films in Prague, and “Munro” got made.