In 1839, the French Academy of Sciences announced the invention of the daguerreotype, the first successful process for creating photographs. Within four years, brothers William and Frederick Langenheim opened a daguerreotype photographic studio in Philadelphia. Their business quickly became one of America's most successful portrait studios.
A daguerreotype is a copper plate covered in a layer of light-sensitive silver. Once this plate was inserted into a camera, it would record a black-and-white picture in astonishingly great detail. However, the process was very slow compared to taking a picture today. The sisters shown here probably had to hold this pose for several minutes. Failure to sit perfectly still would result in a blurry image, so the people being photographed were often held in place with a head clamp or a neck brace.
