Question: what were the most important events of american imperialism era?
Answer: 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.