Social Studies By owensn 1867 Sewards Purchases Alaska 1878 US Conquest of Samoa 1897 Annexation of Hawaii Mar 4, 1897 William McKinley elected president 1898 Sinking of the USS Maine Apr 25, 1898 U.S. Declares War on Spain May 1, 1898 Battle of Manilla Bay Jul 1, 1898 Battle of San Juan Hill Dec 10, 1898 Spanish-American War ends 1899 Open Door Policy Period: 1899 to 1913 Philippine-American War Period: 1899 to 1901 Boxer Rebelion 1900 Foraker Act Mar 2, 1901 Platt Amendment Sep 14, 1901 Assassination of President McKinley 1909 Panama Canal began being built 1914 Panama Canal completed