Abraham Lincoln

This object exemplifies the means by which a photographic image was produced on paper: the glass-plate negative that was the “film” of early photography. Because of their fragility, surviving glass-plate negatives of this size (the so-called “imperial”) are rare: this is one of two of Lincoln that have survived and dates from his August 9, 1863, sitting at Gardner’s Washington studio. The process Gardner used was relatively new to America and consisted of hand-coating a glass plate with collodion—a syrupy mixture of guncotton dissolved in alcohol and ether to which bromide and iodine salts had been added. The difficulty for the photographer was that the glass plate had to be coated with collodion, sensitized in a bath of silver nitrate, and exposed in the camera immediately, while the emulsion was still damp. Gardner was acknowledged as a master in evenly coating the plate, which resulted in prints of exceptional clarity.