In the 1860s, William Mumler photographed ghosts—or so he claimed. Faint images of the dearly departed lurked in the background with the living, like his well-known photo of the recently assassinated Abraham Lincoln comforting Mary Todd. The practice came to be known as spirit photography, and some believed Mumler was channeling the dead. Skeptics, however, called it a fraudulent trick on the gullible, taking advantage of the grieving at a time of suffering and loss. Mumler’s insistence that his work brought back the dead led to a sensational trial in 1869 that was the talk of the nation. In The Strange Case of William Mumler, Spirit Photographer, Louis Kaplan brings together, for the first time, Mumler’s haunting images, his revealing memoir, and rich primary sources, including newspaper articles and P. T. Barnum’s famous indictment of Mumler in Humbugs of the World. Kaplan also contributes two extended essays, which offer a historical perspective of the Mumler phenomena and delve into the sociocultural and theoretical issues surrounding this vivid ghost story. Mumler’s case was an early example of investigative journalism intersecting with a criminal trial that, at its essence, set science against religion. The Strange Case of William Mumler, Spirit Photographer is the definitive resource for this unique and fascinating moment in American history and provides insights into today’s ghosts in the machine.