what were the most important events of american imperialism era?
["Seward's Folly - March 30, 1867. ... ", 'McKinley Tariff - April 15, 1898. ... ', 'US Congress Votes to Go to War With Spain - April 25, 1898. ... ', 'Teller Amendment - July 7, 1898. ... ', 'Annexation of Hawaii - February 6, 1899. ... ', 'Open Door Note - September 6, 1899. ... ', 'Annexation of Philippines - January 1, 1900. ... ', 'Hay-Bunau-Varilla Treaty - January 1, 1904.']