What was the most important reason that president william mckinley asked congress to declare war on spain? a. the business community universally supported the conflict. b. the spanish government had directly provoked and insulted the united states. c. spain refused to end the concentration camps and sign an armistice with cuban rebels. d. mckinley felt that the teller amendment would guarantee that the united states would not establish control of cuba. e. the american public, influenced by the yellow press, and many leading republicans demanded war in the aftermath of the sinking of the maine?

The correct answer is E ... but let's get a bit of context so that the answer makes sense to you.

In 1895, Cuba (located very close to the United States) attempted to overthrow colonial rule by Spain.  The Cuban rebels got financial assistance from people in the United States (private interests, not the US government officially).  Spain responded brutally to the rebellion, and the conflict waged on for a couple of years.  US President McKinley did not want to get the US involved, but American media blasted him as weak for his position.  Then, in 1898, the USS Maine, a battleship of the US navy, which was in the Havana, Cuba harbor, was hit by two huge explosions.  252 men on board died.  The US accused Spain of attacking the battleship, and McKinley went along with calls from Congress to declare war.

By the way, we maybe also should note that it was later discovered that the explosions on the USS Maine were caused by faulty, unstable ammunitions on board the ship blowing up on their own.  But in the mood of the time, going to war with Spain was the only explanation and action the American media and public wanted.