What’s most striking about the category, Singer says, is its “extraordinary emphasis on female heroism.” Protagonists exhibited traditionally “masculine” qualities like “physical strength and endurance, self-reliance, courage, social authority, and the freedom to explore novel experiences outside the domestic sphere.” Then, by the early 1920s, those films and their stars, the so-called “serial queens,” disappeared.

What happened? The answer may have to do with the early film industry’s short-lived tolerance of greater female involvement at all levels of the filmmaking process—a phenomenon that helps explain why today, even after women have shattered so many cultural barriers, action movies still continue to be dominated by male stars.

To understand what happened in the 1910s, it’s necessary to put the emergence of the serial film into context. During this period, two film formats jostled for dominance: what we’d now call “shorts” and “features.” But short films weren’t labeled as “short” at the time—they were simply the industry standard, and were usually described by their length (in number of reels). Features, meanwhile, were the newcomers, with higher production values, more ambitious plots, and greater production costs. Serials were something of a bridge between the two formats. Each episode in a serial was the length of a 15- or 20-minute short film, but over several weeks, a serial could tell a more complicated story.

Serials focused on women action heroes from the start, possibly thanks to the format’s tie-ins with magazines and newspapers, which aimed to draw female readers because they were attractive to advertisers. In 1912, Thomas Edison’s film company teamed up with Ladies’ World magazine to put one of the earliest instances of a serial film, What Happened to Mary?, into print. This example of cross-promotion would continue as other “chapter films” were serialized in newspapers. The Chicago Tribune printed the story of The Adventures of Kathlyn (1913) while the film episodes played in theaters. (Incidentally, Kathlyn was the first film serial to have a narrative thread that continued from week to week instead of relying on the same leading character to provide cohesiveness.)

The focus on heroines seems also to correlate with the film industry’s fascination with the “New Woman.” “She wore less restrictive clothes,” the film curator Eileen Bowser notes, “she was active, she went everywhere she wanted, and she was capable of resolving mysteries.” The proliferation of women in all areas of the film industry during the 1910s—not just as actors, but as screenwriters, theater managers, gossip columnists, film producers, and directors—reflected the increasing number of women in the American workplace, and also the efforts of the vocal and energetic women’s suffrage movement. It’s important to note however, that the abundance of serial-queen films in the 1910s wasn’t caused by women producers or directors pushing for them; the female stars of these movies often provided ideas and sometimes directed, but for the most part, serial films were written and directed by men.