Daguerreotype
Invented by Louis-Jacques-Mandé Daguerre and introduced worldwide in 1839, daguerreotype was almost completely superseded by 1860 with new, less expensive processes yielding more readily viewable images. In the late 20th century, there was a revival of daguerreotypy by a small number of photographers interested in making artistic use of early photographic processes.
Ezra Greenleaf Weld
Of the six daguerreotypes of Douglass that have survived, only one besides Greenleaf's image has had its daguerreotypist identified. Greenleaf's image is unique because it is a group shot at an outdoor meeting rather than a studio portrait. Daguerreotypes were seldom attempted under these circumstances because the long exposure time required made it difficult to get a satisfactory result. Weld's is the only daguerreotype of Douglass whose date is known with certainty. This daguerreotype is also unique in the paradoxical sense that it is the only one known to have been copied. Two original half-plates exist: One is held by the Madison County Historical Society in Oneida, New York, the other is in a private collection and currently on display at the Smithsonian Institution in Washington, D.C. The copy (shown above) is in the J. Paul Getty Museum, Los Angeles, California.