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.
Daguerreotype
The discovery and commercial availability of the halides: iodine, bromine and chlorine a few years earlier (iodine was discovered by Courtois in 1811, bromine by Löwig in 1825 and Balard in 1826 independently, and chlorine by Scheele in 1774) meant that silver photographic processes that rely on the reduction of silver iodide, silver bromide and silver chloride to metallic silver became feasible. The daguerreotype is one of these processes, but was not the first, as Niépce had experimented with paper silver chloride negatives while Wedgwood's experiments were with silver nitrate as were Schultze's stencils of letters. Hippolyte Bayard had been persuaded by Arago to wait before making his paper process public.