American Imperialism By heavymetal Period: Jan 1, 1850 to Dec 31, 1915 American Imperialism A timeline of the Age of American Imperialism Mar 31, 1854 Japan opens ports to American Ships Japan opens ports to American ships Jan 13, 1865 Hawaii becomes U.S territory Jan 13, 1865 Hay Proposes open door policy Mar 30, 1867 William Seward buys Alaska Apr 20, 1898 Spanish American war begins Jan 13, 1900 Boxer Rebellion Jan 13, 1900 US gains Puerto Rico, The Phillipines, and Guam Aug 13, 1913 Panama Canal completed Jan 13, 1915 Panama Canal opens
