Top of page

Collection Civil War Glass Negatives and Related Prints

Taking Photographs During the Civil War

Wagons and camera of Sam A. Cooley, U.S. photographer, Department of the South

During the Civil War, the process of taking photographs was complex and time-consuming.

  • Photographers mixed their own chemicals and prepared their own wet plate glass negatives.
  • The negatives had to be prepared, exposed, and developed within minutes, before the emulsion dried.

It was a difficult process to master in a studio setting and even more difficult to work outdoors. Photographers transported their supplies in a wagon, improvised a darkroom, and learned to use their chemicals in both the blistering heat and bitter cold.

The Wet Plate Process

Producing photographs from wet plates involved many steps.

  • A clean sheet of glass was evenly coated with collodion.
  • In a darkroom or a light-tight chamber, the coated plate was immersed in a silver nitrate solution, sensitizing it to light.
  • After it was sensitized, the wet negative was placed in a light-tight holder and inserted into the camera, which already had been positioned and focused.
  • The "dark slide," which protected the negative from light, and the lens cap were removed for several seconds, allowing light to expose the plate.
  • The "dark slide" was inserted back into the plate holder, which was then removed from the camera.
  • In the darkroom, the glass plate negative was removed from the plate holder and developed, washed in water, and fixed so that the image would not fade, then washed again and dried.
  • Usually the negatives were coated with a varnish to protect the surface.
  • After development, the photographs were printed on paper and mounted.

In the 1880s dry plate negatives were introduced. These glass negatives were commercially available and did not need to be developed immediately after the exposure.