From a review of major April Fools hoaxes, published by National Geographic (March 31, 2004):

On April 1, 1996, readers in five major U.S. cities opened their newspapers to learn from a full page announcement that the Taco Bell Corporation had purchased the Liberty Bell from the U.S. government. The announcement reported that the company was relocating the historic bell from Philadelphia, Pennsylvania, to Irvine, California. The move, the corporation said in the advertisement, was part of an"effort to help the national debt."

Hundreds of other newspapers and television shows ran stories related to a press release on the matter put out by Taco Bell's public relations firm, PainePR. Outraged citizens called the Liberty Bell National Historic Park in Philadelphia to express their disgust. A few hours later the public relations firm released another press announcement stating that the stunt was a hoax.

White House press secretary Mike McCurry got into the act when he remarked that the government would also be"selling the Lincoln Memorial to Ford Motor Company and renaming it the Lincoln-Mercury Memorial."

As a marketing ploy, the hoax was successful, PainePR said on their Web site. The firm says that more than 70 million Americans were exposed to the story, which resulted in a U.S. $500,000 sales increase for Taco Bell on April 1 and a $600,000 increase on April 2.