In recent months, photo id cards have acquired new importance as part of our nation’s fight against terrorism. Digital imaging and magnetic strips are modern developments, but the basic technology behind photo IDs can be traced to the French photographer Adolphe Disdéri, who in 1854 found an efficient process for making miniature portraits. Three years later, the Duke of Parma began attaching photographs of himself to his calling cards. The fad soon spread to England and, in late 1859, to the United States.

By the end of 1860, it was a full-fledged craze on both sides of the Atlantic, as collectors snapped up photos of famous people the way baseball cards are collected today. In one of the earliest examples of sports licensing, when Tom Sayers, the English bare-knuckle boxing champion, defeated the American champion, John Camel Heenan, in England in 1860, and photographers clamored for him to pose for pictures, he replied, “It’s no good, gentlemen, I’ve been and sold my mug to Mr. Newbold.” Whether Newbold had signed up Heenan as well is unknown—“not that it matters greatly” (in the words of one historian), “for after the battle, Heenan’s face was so battered that there was little human semblance left in it.”

It was the Civil War, however, that established card photographs as an American institution. Soldiers on both sides had their pictures taken in uniform before they went off to war and took along pictures of their families and sweethearts. The technology was still fresh in mind when organizers of the 1876 Centennial Exposition, in Philadelphia, needed a way to protect their season passes against use by unauthorized parties.

The procedure they adopted was simple: The recipient of a pass would pose for a photographer under a skylight, usually for 15 to 3 o seconds, or as little as 3 to 5 on exceptionally sunny days. While the picture was being taken, the subject’s head would be immobilized in a brace to hold it completely still, a process that one news account compared to “the tortures of the thumb-screw.” After developing and printing, the photo was cut out and glued to a form. “When [a] pass is presented at the narrow turnstile, which admits only one person at a time,” the account continued, “the gate-keeper compares the photograph with the original; but what provision is made for future growth of beard, shaving, or otherwise changing one’s appearance we can not say.”

Photo IDs eventually spread around the world, showing up as far away as Japan by the early twentieth century. Most notoriously, they were used by the Nazis to register Jewish ghetto residents during World War II. As the century came to a close, photo IDs were nearly universal in America, with most people carrying several (though as late as the early 19905, tradition-loving New York State still did not have photos on its driver’s licenses). The ultimate technological