O'Reilly wrote a book about the Lincoln assassination, and it's loaded with name and detail errors. Historian Edward Steers points out the most fictitious section:
The authors write that she was forced to wear a padded hood when not on trial, and that she was imprisoned in a cell aboard the monitor Montauk, which was “barely habitable.” She suffered from “claustrophobia and disfigurement caused by the hood,” and was “barely tended to by her captors.” “Sick and trapped in this filthy cell, Mary Surratt took on a haunted, bloated appearance.” None of this is true. Mary Surratt was never shackled or hooded at any time. She was never imprisoned aboard the Montauk, but taken to the Carroll Annex of the Old Capitol Prison before being transferred to the women’s section of the Federal Penitentiary at the Washington’s Arsenal.
O'Reilly presents this book as an historical account, but it simply can't be trusted as factual.
Furthermore, how the hell does Bill O'Reilly get to write a book about Lincoln?