The Roff House in Watseka, Illinois, is known for the "Watseka Wonder" a 19th-century event where 13-year-old Lurancy Vennum was purportedly possessed by the spirit of Asa Roff's deceased daughter, Mary, after suffering fits. The haunting is characterized by the spirit recognizing Roff family members, describing unknown items in the house, and communicating through Vennum. The house itself is an 1868 Italianate villa built by the Spiritualist Roffs and is considered America's first documented ghostly possession. The Roff family, prominent Spiritualists, built the house in 1868. After years of Spiritualist rituals, an alleged possession occurred. In 1878, 13-year-old Lurancy Vennum, after suffering epilepsy and trance-like states, claimed to be possessed by Mary Roff. During the 100 days that Vennum was at the Roff house, she displayed uncanny knowledge of the family and the house, recognizing Roff residents and describing items only the family would know. The events were documented in the 1879 book The Watseka Wonder, which detailed the alleged possession and became a bestseller, further cementing the house's haunted reputation. The core of the haunting is the alleged possession of Lurancy Vennum by the spirit of Mary Roff. The spirit of Mary Roff was said to communicate through Vennum, conveying knowledge and recognizing the Roff family members. The event is considered one of the first documented possessions in America, giving the Roff House its unique and enduring haunted legacy.