Cuba was a Spanish colony, and the U.S. gave them formal independence just four years after the war ended. It could easily have been permanently annexed.
Yeah, we just annexed Puerto Rico, Guam, and the Philippines.
Then don't forget the Mexican-American war, which started with our annexation of Texas and ended with our "purchase" of 1.2 million square miles of territory at firesale prices from a conquered opponent.
Life as a Spanish Colony wasn't so hot. Anyways, these areas were granted U.S. citizenship and autonomy soon after.
Earlier, Simon Bolivar, who liberated most of Latin America from Spanish control and laid their democratic foundations, loved the American founding fathers, especially Jefferson, and even sent his nephew to the University of Virginia.
