April 1898 - America went to war against Spain to free Cuba from Spanish domination
May 12, 1898Puerto Rico is overtaken by the United States between July 25 with its landing at Guanica Bay and August 12.
July 7, 1898 - The United States annexes the independent republic of Hawaii.
December 10, 1898 - The Peace Treaty ending the Spanish-American War is signed in Paris.
February 14, 1899 - The United States Congress approves the use of voting machines in federal elections.
September 6, 1899 - The Open Door Policy with China is declared
June 28, 1914 - assassination of archduke
April 24, 1916- Germany wont sink ships without warning
april 16 1917- us enters war
June 1919- treaty of Versailles ; It ended the state of war between Germany and the Allied Powers.