Answer: America sought to impose itself as a world power.
Step-by-step explanation:
The reason for joining the united states is the effort to impose itself as a world power after decades of isolation. In that direction, they acted to exploit the revolution in Cuba that the population sought to achieve because of Spanish dominance. So the cause was the Cuban Revolution, and the real reasons are the effort to make the country stand out on the international front as a vital force.
Many riots and internal problems weakened the Spanish. In such circumstances, America wanted territorial expansion. The end of the conflict brought Cuba independence, but Cuba was under US jurisdiction. The Philippines, Guam and Puerto Rico have become parts of the United States.