The war mainly started because of Cuba’s struggle for independence. Spain wasn't treating Cuba fair and equally, and that’s why they wanted to become independent. The turning point in the Spanish American War is the sinking of the U.S.S Maine. The U.S.S Maine was a battleship sent to Cuba to protect American interest. The sinking of the U.S.S Maine is important because it served as a cause for the Spanish American War, which changed who properly owned Guam, Puerto Rico and let Cuba become independent.