LUBBOCK, Tex. — In December 1953, the inaugural issue of Playboy magazine hit newsstands without a date. Hugh Hefner, its creator, was unsure whether it would be a success and have a future, so by withholding the date he hoped he could continue to sell that issue until he sold out of that first run.

Mr. Hefner, who died on Wednesday at 91, had nothing to worry about.

In its prime, the magazine ranked among America’s top-selling publications, alongside Life and Time, sometimes beating their subscription rates. The magazine, intended for men, quickly transcended Mr. Hefner’s target audience, with a subscriber base that cut across gender, race, class and ideology.

Today it’s easy to write off Playboy, and Mr. Hefner, as the last remnants of a more sexist age. But seen from the perspective of the 1950s and ’60s, they were progressive icons — not just in the libertine styles they promoted, but in the causes that they featured. The magazine became central to what it meant to be a modern man.

The masculine ideal of the era was narrowly defined: aloof, outdoorsy, a breadwinner, “manly.” Showing too much of an interest in culture, fine food or travel was anathema. Mr. Hefner felt trapped by conformity and designed a magazine that promoted a very different idea of what made an individual a “man” through its features and advice on clothing, food, alcohol selections, art, music and literature. Though it quickly became a cliché, many male readers really did “read it for the articles,” telling surveys that they enjoyed features on the ideal bachelor pad even more than the centerfold.