To mark the 200th anniversary of Lincoln's birth on Feb. 12, the long-lost positive transparency of this photograph (above) goes on display beginning tomorrow at the George Eastman House museum of photography in Rochester.

It was sent there for repair in December 2006 by a Midwestern collector of Lincoln materials who didn't realize he owned a national treasure. He has declined to be identified.

"This is the closest you will ever get to seeing Lincoln, short of putting your eyeballs on the man himself," said Grant Romer, the museum's director of photograph conservation.

In 1880, images of the slain Civil War leader were in high demand. Hesler's wet-plate collodion negative was used to create a high-definition, silver-gelatin interpositive - a new-technology format from which several thousand prints were generated.

In 1933, during shipment by parcel post to St. Louis, the original glass plate was accidentally broken and ended up as a shattered artifact in the Smithsonian Institution's vault. The 8-by-10-inch clone - evidently in the same package and similarly damaged - disappeared until its recent resurrection.