Daguerreotype
Morse met the inventor of the daguerreotype, Louis-Jacques-Mande Daguerre, in Paris in January 1839 when Daguerre's invention was announced [2]. While the daguerreotype fascinated Morse, he was concerned about how the new invention would compete with his telegraph. However, Morse's viewing of the daguerreotype alleviated his fears when he saw how revolutionary its technology was. Morse wrote a letter to his brother Sidney describing Daguerre's invention, which Sidney then published in the New-York Observer on April 20, 1839. While this was not the first report of the daguerreotype to appear in America, it was the first in-person report to appear in the United States.
Collodion process
The collodion process is said to have been invented in 1851, almost simultaneously, by Frederick Scott Archer and Gustave Le Gray. During the subsequent decades, many photographers and experimenters refined or varied the process. By the end of the 1860s it had almost entirely replaced the first announced photographic process, the daguerreotype.