Some film historians, like Tom Sito, claim that he helped finance the Warner Brothers' first talkie, The Jazz Singer (1927).

[6][7] He then secured a contract with the studio to produce its brand-new Looney Tunes series, and he signed animators Hugh Harman and Rudy Ising to create these cartoons with their Bosko character as the star.

One of these was Friz Freleng, whom Schlesinger promoted to oversee production of Looney Tunes and to develop the sister series, Merrie Melodies.

Schlesinger's recruiting of Robert McKimson, Tex Avery, Chuck Jones, and Frank Tashlin further increased the quality of the studio's output.

He later added Carl Stalling and Mel Blanc, and collectively these men created such famous characters as Porky Pig, Daffy Duck, and Bugs Bunny.

Schlesinger largely took a "hands off" approach to the animation unit, allowing his directors freedom to create what they wished, provided that the resulting films were successful.

One oft-repeated story states that Mel Blanc patterned the voices of both Daffy Duck and Sylvester the Cat on Schlesinger.

[9] However, in Mel Blanc's autobiography, That's Not All Folks!, he contradicts that conventional belief, writing "It seemed to me that such an extended mandible would hinder his speech, particularly on words containing an s sound.