PBS
Pbs: American Experience: Hawaii's Last Queen
This transcript from an American Experience program about Hawaii's last queen, Lili'uokalani, tells of her enlightened rule of Hawaii and the overthrow of her monarchy, which resulted in the U.S. annexation of Hawaii.
Other
On Line History of the United States: The Age of Imperialism
Online history page containing numerous links to specific incidents of U.S. expansion in the Pacific, Latin America, China, and Cuba.
Other
Expansion in the Pacific: Footholds in the Pacific
Good description of 19th century Hawaiian history and its annexation by the U.S., with links to related maps, pictures, and treaties.
Gilder Lehrman Institute of American History
Gilder Lehrman Institute: History Now: Empire Building
[Free Registration/Login Required] A lengthy essay about American focus on foreign affairs after the Civil War, expanding particularly in the late 19th century. Read about U.S. exploits in the Caribbean, Latin America, and the Pacific...
University of Groningen
American History: Outlines: Ambivalent Empire
Overview of U.S. domestic, foreign and colonial policy during an era of U.S. expansion and imperialism.