Hearst's New York Journal front page giving a biased, pro-war account of the explosion on the U.S.S. Maine (Wikipedia)

By the end of the 19th century, Cuba had long been seen as a potential acquisition for the expanding United States. By the 1860s, Cuba was importing many of their goods from the United States, who purchased most of the sugar that the island produced. Several attempts to purchase the island from Spain were aborted due to shifting political fortunes within the U.S. Large American companies had a significant financial interest in lowering import tariffs on the sugar, while at the same time the mindset of “Manifest Destiny” – the drive to expand the U.S. throughout the Western Hemisphere – was beginning to take hold.

Enter the media. Beginning in the 1890s, William Randolph Hearst, Joseph Pullitzer, and other members of the media began to conjure and over-report ‘attrocities’ that they claimed had been perpetrated by the Spanish Empire, which was now in steep decline. During this time, Hearst’s New York Journal and Pullitzer’s New York World entered into a fight for readership. They began to employ strategies to gain readership that would later be called “Yellow Journalism”. This included publishing morality plays, showing “nudity” (or the closest Victorian equivalent), and sensational political articles about sometimes fabricated scandals.

During the 1890s, Cuba began a struggle for independence against Spain. Hearst and others could see the potential for readership in the headlines. At one point, World correspondent as James Creelman wrote in his log, he sent a message from Cuba to Hearst saying “There will be no war.” Hearst replied, “Please remain. You furnish the pictures and I’ll furnish the war.”

Later, the U.S. sent a dreadnought, the U.S.S. Maine to Havana to guard American interests as hostilities broke out there. It sank, likely the result of an internal boiler explosion, but Hearst’s headline was “MAINE EXPLOSION CAUSED BY BOMB OR TORPEDO”. Pullitzer’s Journal screamed, “DESTRUCTION OF THE WAR SHIP MAINE WAS THE WORK OF AN ENEMY” above an illustration of a terrible explosion splitting the ship in two pieces. The headlines helped to begin the Spanish-American War.

Three years later, Ambrose Bierce claimed that Hearst’s reporting led Leon Czolgosz to shoot President McKinley. These claims devastated Hearst’s hopes to become president himself, but he denied it to be the case.

Later, in 1941, Frank Luther Mott gave a description of signs of “Yellow Journalism”:

1. scare headlines in huge print, often of minor news
2. lavish use of pictures, or imaginary drawings
3. use of faked interviews, misleading headlines, pseudo-science, and a parade of false learning from so-called experts
4. emphasis on full-color Sunday supplements, usually with comic strips
5. dramatic sympathy with the “underdog” against the system.

How many are still in use today?

Wikipedia: Yellow Journalism