Where were the targets of the Cuban guerrillas?Why did President McKinley finally send the USS Maine to Havana?

Cuba has a long history of guerrilla warfare and insurrection.  Since the USS Maine was referenced, I will limit my answer to the activities of guerrillas operating within the 5 years prior to the Spanish American War.  The Mambi (The guerrillas were called the Mambises by the Spanish.) leaders landed on Cuba in 1895.  The primary leader was Jose Marti who was killed in battle not long after the landing.  In the beginning, guerrilla activity was limited primarily to the eastern 3 provinces of the island and focused on surrounding large towns and cities.  However, most of the wealth and government installments were located in the western provinces of Cuba.  The Spanish tried to limit the guerrillas to the eastern part of the island by creating a defensive line called a "trocha" across the middle of the island from Jucaro to Moron.  However, the Mambises were able to defeat the trocha in 1896 and bring the war to the western provinces.  

President McKinley sent the USS Maine to Havana in 1898 in response to a riot by pro-Spanish Cubans.  The rioters destroyed several newspapers critical of the Spanish government.  The USS Maine was ordered to Havana to protect American lives and interests.