I n 1860, Mathew Brady was one of the world's best-known photographers.

His book, "The Gallery of Illustrious Americans," published 10 years earlier, had made him famous. Those who had sat in his studio and faced the large box on the wooden tripod included Daniel Webster, Edgar Allan Poe and Henry Clay.

So when Republican operatives wanted the perfect picture of presidential candidate Abraham Lincoln, they took him to Brady's studio on Broadway in New York City. Brady looked at the tall, gangly man with the rugged, clean-shaven face. He pulled up his shirt collar so his neck wouldn't look so long. He brushed down his hair and placed his hand on a book. Later, as Brady developed the photo, he retouched it so Lincoln's facial lines wouldn't be so harsh.

Brady produced a remarkable image. At that time most Americans hadn't seen Lincoln, and his opponents had caricatured him as a wild frontiersman. Yet here he was -- extremely tall, standing erect, an imposing gentleman in a long frock coat. The Brady photo was used for engravings and reprinted in the major weeklies of the day, Harper's Weekly and Frank Leslie's Illustrated Newspaper. It also appeared on a campaign button.

The same day he sat for Brady -- Feb. 27, 1860 -- Lincoln gave one of his most important speeches, the Cooper Union address. He spoke 7,000 words to an audience of influential businessmen, ministers, scholars and journalists. The speech was front-page news the next day. In an interview years later, very aware of his role in history, the photographer repeated what Lincoln reportedly said about the confluence: "Brady and the Cooper Institute made me president."

Brady was born in Warren County, N.Y., in 1823. As a young man in New York City, he studied photography with Samuel Morse. (In addition to inventing the electric telegraph and Morse code, Morse is credited with bringing the daguerreotype process from France to the United States.) When Brady was introduced to daguerreotypes in the 1840s, photography was still a new art form and -- at a time when most newspapers still relied on sketches -- an extremely uncertain business venture. Nonetheless, Brady opened his first photography studio in 1844; by the following year he had won a national competition for the best colored and best plain daguerreotypes.

He operated his studio like a painter's workshop, assigning colleagues and apprentices to various tasks. Studio personnel operated the cameras after Brady set up the shot, a practice he may have adopted because of the poor eyesight that had plagued him since childhood. The photographer and his assistants posed their subjects. They became skilled at injecting personality into the images, much like formal portrait painters. Brady's artistry was leavened with promotional acumen. As was the custom of the times, the studio's photographs were reprinted on tiny cards called "cartes de visite," making his work greatly accessible.

"Brady developed a reputation because of his quality and his marketing skills," said Ann M. Shumard, curator of photographs at the National Portrait Gallery. "He was a good promoter and supplied images that could be reproduced. He adapted to the times."

Edward McCarter, supervisory archivist for still pictures at the National Archives, concurred.

"Brady was the best-known entrepreneur of the day," McCarter said. "You might get an argument on whether he was the best photographer."

In 1858, Brady set up a second studio on Pennsylvania Avenue in Washington, across the street from the present location of the National Archives. (He did his printing on the roof.) He came to the city seeking greater proximity to the power brokers of the day, and his subjects included John Quincy Adams, Dolley Madison, Washington Irving, James Fenimore Cooper, Jenny Lind, Sojourner Truth, Thomas J. "Stonewall" Jackson, William Cullen Bryant, Jefferson Davis, Ulysses S. Grant and Robert E. Lee. He even photographed the actor Edwin Booth and his brother John Wilkes Booth. His interest in documenting the era's notables foreshadowed the art of celebrity portraiture.

"From the first I regarded myself as under obligation to my country to preserve the faces of the historic men and mothers," Brady said in a 1891 article in the New York World. (Historians think the interview, one of the few given by Brady, is greatly embellished. It also includes a rare physical description of the aging photographer: "Mr. Brady is a person of trim, wiry, square-shouldered figure, with the light of an Irish shower-sun in his smile.")