* Theodore Roosevelt: President of the United States from 1901 to 1909, Roosevelt was a strong advocate of American imperialism and expanded the United States' presence in Latin America, the Caribbean, and the Pacific.
* Woodrow Wilson: President of the United States from 1913 to 1921, Wilson continued to pursue an imperialist policy, intervening in Latin America and the Caribbean and entering World War I on the side of the Allied Powers.
* Alfred Thayer Mahan: A naval strategist and historian, Mahan argued that the United States needed a strong navy in order to protect its interests and expand its power. His ideas were influential in the development of American naval policy during the late 19th and early 20th centuries.
* Cecil Rhodes: A British statesman and businessman, Rhodes was a leading proponent of British imperialism in Africa. He founded the De Beers diamond company and played a key role in the colonization of Rhodesia (present-day Zimbabwe).