Sisters Kate (1838–92), Leah (1814–90) and Margaret (1836–93) Fox played an important role in the creation of Spiritualism, especially of Spiritism.

In 1848, the two younger sisters – Kate and Margaret – were living in a house in Hydesville, a village near Rochester, New York with their parents. The house had some prior reputation for being haunted, but it wasn't until late March that the family began to be frightened by unexplained sounds that at times sounded like knocking, and at other times like the moving of furniture. During the night of March 31, Kate challenged the invisible noise-maker to repeat the snaps of her fingers. It did. It was asked to rap out the ages of the girls. It did.

The neighbors were called in, and over the course of the next few days a type of code was developed where raps could signify yes or no in response to a question, or be used to indicate a letter of the alphabet. The entity creating the sounds claimed to be the spirit of a pedlar named Charles B. Rosma, who had been murdered five years earlier and buried in the cellar. The neighbors dug up the cellar and found a few pieces of bone, but it wasn't until 1904 that a skeleton was found, buried in the cellar wall. No missing person named Charles B. Rosma was ever identified.