What was the term used to describe the sensationalist newspaper reporting that stirred up war fever?

The sensationalist newspaper reporting that stirred up war fever was called yellow journalism.

The term described reporting that emphasized dramatic headlines, emotional stories, exaggerated claims, and sometimes fabricated or poorly verified allegations. In the 1890s, it became closely associated with the fierce circulation rivalry between Joseph Pulitzer’s New York World and William Randolph Hearst’s New York Journal.

The phrase came from “The Yellow Kid,” a popular comic-strip character whose speech appeared in yellow ink. Both newspapers competed to publish the strip, and the character’s color helped inspire the name for the broader sensationalist style. Coverage of Spanish actions in Cuba, including alleged atrocities, helped intensify American public anger before and during the Spanish-American War.

Yellow journalism is often blamed for causing the war by itself, but that is too simple. Cuban resistance to Spanish rule, economic interests, political pressure, the destruction of USS Maine, and public sympathy for Cuban rebels also mattered. Jingoism describes aggressive nationalism, while propaganda is a broader term; neither is the specific newspaper style named in this question.