Final answer:
The US declared war on Spain to aid Cuba in its independence, influenced by economic interests, anti-colonial sentiment, and the USS Maine incident, leading to the Spanish cession of territories and enhanced U.S. presence in global politics.
Step-by-step explanation:
Intentions of the US in the Spanish-American War
The United States entered the conflict with Spain primarily to support the Cuban struggle for independence. American public opinion and Congressional attitude were swayed by the atrocities committed by Spanish forces, the economic interests of American businesses in Cuban resources, and a zeal to assert America's stance on anti-colonialism in the Western Hemisphere, in line with the Monroe Doctrine. The pivotal event that led to the declaration of war was the mysterious explosion of the USS Maine in Havana harbor, which was widely attributed to Spanish sabotage by the American press. President McKinley also sought to reassure those against imperialist ambitions by attaching the Teller Amendment to the war declaration, which explicitly stated that the United States had no intention of annexing Cuba.
The consequences of the war included the end of Spanish sovereignty in the Caribbean, with the Spanish Crown ceding Puerto Rico, Guam, and the Philippines to the U.S. While the Platt Amendment imposed by the U.S. ostensibly sought to protect Cuba's independence, it paradoxically allowed significant U.S. intervention in Cuban affairs. The war symbolized a turning point for the U.S., marking its emergence as a global power with heightened involvement in international politics, particularly in the Caribbean region.