Ka cika wannan jumla: McKinley shi ne shugaban ƙasa a lokacin Yaƙin Spain da Amirka na 1898, wanda ya sa Amirka ta yi nasara nan da nan. A matsayin sashe na yarjejeniyar zaman lafiya, Spain ta ba da mulkin mallaka na ƙasashen waje na Puerto Rico, Guam, da Philippines ga Amurka. Tare da al'umma mai wadata, McKinley ya sake kayar da Bryan a zaben shugaban kasa na 1900.
Shugaban McKinley ya kashe Leon Czolgosz a watan Satumbar 1901, kuma Mataimakin Shugaban Theodore Roosevelt ya gaje shi.