Photography in the United States
In spring 1839, the daguerreotype was introduced into the United States by an Englishman named D.W. Seager, who took the first photograph of a view of St. Paul’s Church and a corner of the Astor House in Lower Manhattan in New York City. Painter and inventor Samuel Finley Breese Morse had met Louis Daguerre in Paris in the spring of 1839, becoming the first American to see his photographic process and becoming enamored with it as a result. When he returned to the United States later that year, he enthusiastically promoted the daguerreotype while hailing Seager's prototypical image. Morse had painted "The Gallery of the Louvre" in 1833, and the appeal of the medium of the daguerreotype was an obvious one to him: it was a means of making faithful copies of artworks, in addition to anything else that would be still in front of the slow eye of the camera.
History of the camera
After Niépce's death in 1833, his partner Louis Daguerre continued to experiment and by 1837 had created the first practical photographic process, which he named the daguerreotype and publicly unveiled in 1839. Daguerre treated a silver-plated sheet of copper with iodine vapor to give it a coating of light-sensitive silver iodide. After exposure in the camera, the image was developed by mercury vapor and fixed with a strong solution of ordinary salt (sodium chloride). Henry Fox Talbot perfected a different process, the calotype, in 1840. As commercialized, both processes used very simple cameras consisting of two nested boxes. The rear box had a removable ground glass screen and could slide in and out to adjust the focus. After focusing, the ground glass was replaced with a light-tight holder containing the sensitized plate or paper and the lens was capped. Then the photographer opened the front cover of the holder, uncapped the lens, and counted off as many minutes as the lighting conditions seemed to require before replacing the cap and closing the holder. Despite this mechanical simplicity, high-quality achromatic lenses were standard.