Abe Lincoln knew how to play to the camera. His last living portrait, taken by Alexander Gardner four days before the assassination, has a weary, introspective expression that's still more powerful than any contemporary media personality. He appears a human if formal president, with his tie a bit crooked. The plate was cracked in the printing process and only his eyes are in sharp focus; the shallow depth of field makes his hairline a blur. This is the Lincoln we have made an American icon.

Gardner's Lincoln is the best-known portrait in the Frederick Hill Meserve Collection, 70 examples of which are newly installed in a rose-colored corner of the National Portrait Gallery. The rest are tributes to the documentary skills of Mathew Brady -- in fact, the room was designed to resemble his studio-gallery -- and prints from 5,400 Brady glass-plate negatives acquired by the gallery will be rotating exhibits there. Brady's client register, a negative box and four-tube Carte-de-Visite camera, circa 1879, are also on view.

(William F. Stapp, curator of photos, notes there was one very last photograph of Lincoln, taken in the casket. But the negatives were ordered destroyed and only one survived. It's in the possession of a Lincoln historical society and not part of this show.)

Brady's subjects were the movers and shakers of the American Civil War. Lincoln in the penny pose, Mary Todd in her Inaugural gown, pompous and relaxed generals, stage and literary figures, scientists and explorers are all preserved with exceptionally clear quality. Ambrose Everett Burnside, the Union general whose bushy side whiskers gave rise to the term "sideburns;" Edwin Booth, John Wilkes's brother, a Shakespearean actor in a Napoleonic pose; Ulysses S. Grant, William Tecumseh Sherman, Henry Wadsworth Longfellow, Jefferson Davis, Andrew Johnson, Hamilton Fish -- they're all surprisingly fresh faces. It's as though 115 years have been obliterated by the immediacy of the medium.

"From the very first I regarded myself as under obligation to my country to preserve the faces of its historic men and mothers," Brady said in 1891. The Portrait Gallery passes along his dutiful work, with only a tad of confusion as to each subject's identifying label. THE FREDERICK HILL MESERVE COLLECTION -- At the National Portrait Gallery, F and Eighth Streets NW, on view indefinitely. graphics /photo: "The Last Lincoln," from the Brady studio.