Which factor is most closely associated with the decision of the united states to declare war on spain in 1898?

The answer is yellow journalism. The Spanish–American War (April–August 1898) is thought to be both a defining moment in the historical backdrop of purposeful publicity and the start of the act of yellow journalism. Yellow  journalism made support for the Spanish-American War by composing articles about the sinking of the United States war vessel Maine in Havana Harbor

Ithink it is called reservation