Bill O’Reilly defended his history book “Killing Lincoln” on Monday after a National Park Service review last week said it contained factual errors and lack of documentation. The Fox News host said the bestseller was “under some fire from the forces of darkness.”

Speaking on “The O’Reilly Factor,” he acknowledged that “Killing Lincoln” contained “four minor misstatements, all of which have been corrected.” He added that “there are also two typeset errors.”

After the review conducted by Rae Emerson, the deputy superintendent of Ford’s Theatre National Historic Site, the National Park Service recommended that the book not be sold in the Ford’s Theatre basement museum bookstore.

However, Ford’s Theatre Society, which operates Ford’s Theatre in partnership with the park service, has the book for sale in its gift shop in the ground-floor lobby. Paul R. Tetreault, director of Ford’s Theatre Society, said, “While we understand the National Park Service’s concerns about the book, we decided to let our visitors judge the book themselves.”

Henry Holt, the publisher of “Killing Lincoln,” said Monday that it has corrected mistakes in the book, which O’Reilly wrote with Martin Dugard.

“Once we were made aware of the errors in the book, corrections were made in subsequent printings of ‘Killing Lincoln,’ ” Pat Eisemann, Henry Holt’s director of publicity, said in an e-mail. “We continue to fully support the work of the authors.”

O’Reilly said he has invited Emerson onto his show and noted that the book has more than 1 million copies in print.

Other readers besides Emerson have said they found historical inaccuracies in the book. Historian Edward Steers Jr., writing in the November issue of “North & South — The Official Magazine of the Civil War Society,” said that O’Reilly and Dugard misidentified the chief carpenter for theater owner John Ford; provided a wrong figure for the number of acres on the farm of Samuel Mudd, the doctor who was convicted of conspiring in the assassination; and incorrectly portrayed the conditions of conspirator Mary Surratt’s imprisonment.

Emerson said she found, among other inaccuracies, that the authors were wrong about the number of times the play “Our American Cousin” was performed at Ford’s Theatre before Lincoln saw it on the night of his assassination, and that they mistakenly placed Lincoln in the Oval Office, which was not created at the White House until 1909, during the Taft administration.

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Bill O’Reilly’s ‘Killing Lincoln’ not for sale at Ford’s Theatre museum bookstore