I found this story on Futility Closet's blog here. The original source was the Salem Register, 1827, quoted in The Olden Time Series, Vol. 6: Literary Curiosities: Gleanings Chiefly from Old Newspapers of Boston and Salem, Massachusetts, 1886.
The below are excerpts from newspapers in which, through the accidental omission of a single letter in a single word (seen here in italics), the entire meaning of the sentence was changed. Quite unfortunately.
-“The conflict was dreadful, and the enemy was repulsed with considerable laughter.” [meant to be "slaughter".]
-“Robert Jones was yesterday brought before the sitting Magistrate, on a charge of having spoken reason at the Barleymow public-house.” [meant to be "treason".]
-“In consequence of the numerous accidents occasioned by skaiting on the Serpentine River, measures are taking to put a top to it.” [meant to be "stop"].
-“When Miss Leserve, late of Covent Garden Theatre, visited the ‘Hecla,’ she was politely drawn up the ship’s side by means of a hair.” [meant to be "chair".]
-“At the Guildhall dinner, none of the poultry was eatable except the owls.” [meant to be "fowls".]
-“A gentleman was yesterday brought up to answer a charge of having eaten a hackney-coachman for having demanded more than his fare; and another was accused of having stolen a small ox out of the Bath mail; the stolen property was found in his waistcoat pocket.” [meant to be "beaten" and "box".]