Historically established causes of the the Spanish-American War (1898) are the sinking of the battleship U.S.S. Maine and a series of yellow journalism publications that criticized Spanish Cuba administration.
However, the historical importance of this war for American history, and the place the US occupies in the world after it, makes this historical event object of many reinterpretations.
Recent historians have called this conflict Spanish-American-Cuban-Filipino War in order to fully represent every major participant and interests at stake.
At that moment the world was going through a change in international power balance. For example, Great Britain and Spain were dying powers, seeing many colonies seeking independence; Japan, Germany and the US, in their turn, were growing and developing new international interests.
Because of the country's expansion and need for new consumer markets, and US's following attack on Cuba's autonomy after the end of the war (turning Cuba into a US'S protectorat and the Platt Amendment which denied Cuba's self-determination). That's why amongst the causes of the war one can not say the US seeked for Cuba's self-determination and right to be free from Spanish's atrocities.
Cuba being so close to the US and also representing an opportunity for new markets, it was in the US's interest that any kind of social revolution didn't take place there. The sinking of the U.S.S. Maine was probably no more than an excuse.