The correct answer should deal with American Expansion or American Imperialism.
All these events represent the United States interest in expanding their power and influence on a global scale.
For example, the Spanish-American War resulted in the US developing relations with Cuba and also acquiring the territories of Guam, Puerto Rico, and the Philippines.
The acquisition of Hawaii also shows America's commitment to expansion, as the US took control of these islands that were roughly 2,500 miles away from the United States.
Lastly, the Open Door Policy allowed for trading with China, resulting in expanded American trade opportunities.