[161] Foreseeing difficulty in getting two-thirds of the Senate to approve a treaty of annexation, McKinley instead supported the effort of Democratic Representative Francis G. Newlands of Nevada to accomplish the result by joint resolution of both houses of Congress.[162] The resulting Newlands Resolution passed both houses by wide margins, and McKinley signed it into law on July 8, 1898.[162] McKinley biographer H. Wayne Morgan notes, "McKinley was the guiding spirit behind the annexation of Hawaii, showing ... a firmness in pursuing it";[163] the president told Cortelyou, "We need Hawaii just as much and a good deal more than we did California. It is manifest destiny."[164]

Expanding influence overseas
Open door in China
Even before peace negotiations began with Spain, McKinley asked Congress to set up a commission to examine trade opportunities in Asia and espoused an "Open Door Policy", in which all nations would freely trade with China and none would seek to violate that nation's territorial integrity.[165]

American soldiers scale the walls of Beijing to relieve the siege of the International Legations, August 1900
American missionaries were threatened with death when the Boxer Rebellion menaced foreigners in China.