By the mid-1850s, new photographic processes had revolutionized the public’s relationship to images. Although still one-of-a-kind objects, tintypes are darker and lower in contrast than daguerreotypes; but their quickness and affordability meant they remained popular into the 20th century. To produce one, a lacquered sheet of iron (not tin) was coated with collodion and then soaked in silver nitrate; the plate was exposed while the solution was still wet, then developed and fixed immediately. The entire process could take just 15 minutes, which meant itinerant photographers could set up instant studios in places like parks or even military camps.

That might be where this image of two Union soldiers was taken. Their faces are serious but they perform for the camera, pretending to eat hardtack, the cheap and long-lasting crackers that sustained surveyors, gold miners, and soldiers. Demand for photographs accelerated during the Civil War, as both soldiers and those they left behind sought souvenirs of their loved ones.

—Text taken from the Carter Handbook (2023).