If you were writing a thesis paper about events that legitimized the united states as an international power, which of the following would be most effective to include?

The one that is the msot effective to include is US victory in the Spanish-American War in 1898.
US victory in the Spanish-American War in 1898 basically help the majority of South American region to obtain their independence in the spanish.
This result of this war opened up a mutually beneficial relationship between us and southern american nations in term of trades, resources exchange, millitary alliance, etc.