By Marianne Szegedy-Maszak

Adah Isaacs Menken was a 19th-century American actress of modest talent, undistinguished features–and spectacular celebrity. Long before Marilyn Monroe or Liz Taylor commanded first-name intimacy with the public details of their private lives, Menken carefully and cleverly cultivated her reputation. There was the bad first marriage in which she punched her famous boxer husband and gave him an even more famous black eye. There were the requisite scandalous romances with famous men. But above all, writes critic Vicki Goldberg in The Power of Photography, there were the pictures. When photographs appeared showing Menken sitting on the lap of aging Three Musketeers author Alexandre Dumas in 1867, there was public outcry. Dumas was wearing no jacket! He had his arm around her! Parisians were scandalized–and bought the photographs wherever they could.

From Mathew Brady's portraits of Lincoln to the paparazzi shots of Princess Di, "it is hard to imagine that we would be as fascinated with celebrity as we now are if photography had never been invented," says Sarah Greenough, curator of photographs at the National Gallery of Art. Without photography, a movie star, a billionaire, or a Nobel Prize winner would be just that. With photography they become animal lovers, doting parents, expert gardeners. As Leo Braudy, professor of English at the University of Southern California and author of The Frenzy of Renown: Fame and Its History, explains, the visual accessibility of these images creates "a larger kind of fame family in which you can have not-quite-imaginary, almost tangible emotional relationships" with famous strangers.

Possessing an image of someone–taking that image into your home, studying it at leisure–makes that person an oddly intimate part of your life. Much as religious icons create a direct connection with a saint, cheap, relatively easy-to-reproduce photographic images make it possible for millions to own their own icons–the secular saints of celebrity. "The interest in who is depicted is so much greater than how the person is presented," says Greenough. "My daughter would probably be just as intrigued by a picture of Ben Affleck if it were in People" as she would be if it were one "[Edward] Steichen had taken."

Before photography, portraits and sculptures of the famous were primarily restricted to the privileged. Then, in 1854, André-Adolphe-Eugène Disdéri, a Parisian portrait photographer, figured out how to make multiple exposures of the same image by dividing a single plate of glass into eight to 12 rectangles. After the photograph was shot and the images cut up, the small pictures were mounted on pieces of paper like calling cards. Suddenly, highly detailed images could be quickly and cheaply reproduced. Called a carte de visite, the little image was immediately popular: By the 1860s, "cartomania" had swept America and Europe, so that by mid-decade a business like Anthony & Co. produced over 3,600 cartes of celebrities every day. A carte of Alexandra, Princess of Wales, sold 300,000 copies.

Sound familiar? The pose may not be as formal, the subject not necessarily royal, but the cartes that propelled Adah Isaacs Menken to fame foreshadow the Vanity Fair cover that propelled a naked, pregnant Demi Moore to new levels of celebrity. First, there is the strictly commercial element: Just as Menken's image sold cartes, Moore's image sold magazines. But photography also provides that crucial alliance of technology and widespread distribution that generates and feeds the public's celebrity-mongering.

The introduction of halftone printing in 1880 revolutionized reading material by making it possible for photographs and text to be easily printed together on the same page. As soon as that happened, write Carole Kismaric and Marvin Heiferman in Fame After Photography, "A new mass media quickly came to rely on pictures of the beautiful and powerful, the noted and the notorious, for content, excitement, and economic survival."

When Conde Nast hired Steichen as the principal photographer for Vanity Fair and then for Vogue in the early 1920s, a more sophisticated technology made it possible for his photographs to sustain portrait-quality elegance, even for a general-audience glossy. His portraits of the era's beautiful people included a haunting photo of Greta Garbo, taken on a movie set. Steichen complained about the curly hairstyle she had been given for her role. Garbo agreed and angrily pushed her hair off her face. In that split second, Steichen captured her stunning, and defiant, beauty.

Technology made celebrity a mass commodity, but photography also added a narrative element to the lives of the famous. Photographs reinforce the public's sense of understanding the celebrity's real persona, either by embodying the cliché–Jack Nicholson, middle finger extended–or by contradicting it–Hillary Clinton crying. Biographies of Liz Taylor, for example, or Ben Affleck, are now constructed as much around visuals as around events. Perhaps more.

Liz Taylor's life–from the beautiful young girl of National Velvet, to the oft-married movie star with a tendency to avoirdupois, to the chronically ill tabloid caricature she has now become–would have been a very different life, had not the camera recorded it. "I am my own commodity," Taylor once said of her over-the-top fame–a celebrity that made her the visual heir to the extremely famous, and now long-forgotten, Adah Isaacs Menken.