To make the image, a daguerreotypist polished a sheet of silver-plated copper to a mirror finish treated it with fumes that made its surface light sensitive exposed it in a camera for as long as was judged to be necessary, which could be as little as a few seconds for brightly sunlit subjects or much longer with less intense lighting made the resulting latent image on it visible by fuming it with mercury vapor removed its sensitivity to light by liquid chemical treatment rinsed and dried it and then sealed the easily marred result behind glass in a protective enclosure.
Congressman-elect in 1846, attributed to Nicholas H. The first authenticated image of Abraham Lincoln, a daguerreotype of him as U.S.
