[4] They arrived in the Jewish neighborhood of New York City's Lower East Side and, as was common at the time, adopted Anglicized names: His parents became Julius and Minnie Liebowitz, while he became Jacob, soon shortened to Jack.

Although a chance meeting, the two men complemented each other very well—Donenfeld was a social, chance-taking high-flyer, while Liebowitz was cautious and had a logical mind that ensured Donenfeld's fiscal mistakes were small, and that his business promises were binding only in favor to himself.

[10] When Liebowitz first worked for Donenfeld, the latter's empire was little more than a publishing house for "sex pulp" and art nudie magazines distributed by Eastern News, a company run by Charles Dreyfus and Paul Sampliner.

A compromise was called for, and Donenfeld, not wanting to find himself hamstrung by a distributor again, approached Sampliner with the idea of creating the Independent News Company, a publishing house with its own distribution system.

[11] As a publisher, Donenfeld had managed to dodge creditors and break deals, but as a distributor, he came to rely more on Liebowitz to ensure that the company ran smoothly.

[12] In 1935, Major Malcolm Wheeler-Nicholson came to Independent News seeking a new distributor for the comic book projects his company, National Allied Publications, was producing.

[13] As part of the bankruptcy action, Liebowitz—now sole owner of Detective Comics Inc.—bought up Wheeler-Nicholson's National Allied Publications, and Donenfeld and Liebowitz assumed control over the entire, growing comic-book publisher.

[14] He asked editor Vin Sullivan to find material to fill the new title, and Sullivan, Liebowitz and Sheldon Mayer ultimately created comics history and kickstarted what historians and fans call the Golden Age of Comic Books by selecting writer Jerry Siegel and artist Joe Shuster's character Superman to star in the new title.

As the years went by, Liebowitz stayed at the forefront of new technologies and entertainment media, helping oversee Superman's transition to movie serials starring Kirk Alyn; to radio; and to theatrical animated shorts.

[16] Liebowitz continued to be an active member of the Warner Communications board, visiting his office daily even into his 91st year, finally relinquishing his place in 1991.

The first was Martin Goodman's publishing company (whose staff would later form Marvel Comics), Bill Gaines's Mad magazine[18] and Hugh Hefner's Playboy.