On June 25, 1899 an interesting story about the Great Wall of China appeared in three Denver newspapers. It said that the Chinese were going to tear the Great Wall down and build a road in its place, and that to complete this project they were taking bids from American firms.
The news supposedly came from a Chicago engineer, Frank C. Lewis, who was one of those bidding for the job. From Denver the story made its way to Chicago and the East Coast where it appeared as front page news in numerous papers. Of course, not a word of the story was true. It had been created as a joke by three reporters working on separate Denver papers to spice up a slow news day.
The story might have ended there and been remembered as nothing more than a minor hoax, but many years later a rumor began to circulate about what happened when the news reached China.
Supposedly the Chinese had been infuriated by the hoax and took up arms against Westerners in retaliation, thus starting the Boxer Rebellion. This rumor grew and grew until it reached the official status of fact. It proved to be (and continues to be) a popular morality tale told by preachers to their congregations in order to demonstrate the harmful consequences of lying.
But in actuality the Great Wall of China hoax had nothing to do with the Boxer Rebellion. The idea that it did has been traced to a 1939 article by Harry Lee Wilber that appeared in the North American Review. Apparently Wilber was guilty of that old journalistic strategy of taking a good story and improving it.
References: Harry Lee Wilber, "A Fake That Rocked the World," in Great Hoaxes of All Time, Robert Medill McBride and Neil Pritchie (eds.), Robert C. McBride Co., New York, 1956: 17-24