Why was the US interested in Cuba, Hawaii, and the Philippines?
Big Business was interested in the creation of new markets.
The US intervention in the Pacific and Cuba happened at the height of the Gilded Age during which major corporations took control of the American government and wanted it to defend their interests. They thought colonies for the USA would create new markets by bringing new consumers and ew producers in the American economy.
It was accepted by the American people because of the Yellow Press(Hearst, Pulitzer) which promoted it and because of the feeling of nostalgia for the conquest of the West(after the closure of the frontier in 1890 according to the Census Bureau).