The Boxer Rebellion reached its height during the summer of 1900. Previously, European powers and Japan had taken advance of turmoil in China following that country’s defeat in the Sino-Japanese War of 1894-1895 by dividing China into spheres of influence. President McKinley and Secretary of State John Hay tried to safeguard Chinese territorial integrity and free trade through the Open Door policy, announced in 1899. Domestic resentment of foreign intervention in China led to the establishment of I-ho ch’üan (“Righteous and Harmonious Fists”), called “Boxers” in the West because of their belief that mystical boxing rituals protected them from bullets. The Boxers were primarily a religious society that initially focused its wrath on Christian missionaries and Chinese converts to what was viewed as a Western religion. Their agenda soon expanded to the eradication of all foreign presence and influence in China.

In 1898, the Boxers led a rebellion in Shantung province and quickly gained adherents in the Chinese capital of Peking (Beijing). The ruling Manchu court was ambivalent about the movement, pleased by its anti-foreign drive but concerned about its destabilizing affect on China, and took a neutral stance at first. By the spring of 1900, however, the Ch’ing administration had given its secret blessing to the Boxers. In early June, an international military force of 2000 sailed from Tientsin to Peking, where the Boxers were burning foreign property and killing foreign nationals and Chinese Christians. Meanwhile, the Empress Tz’u-hsi declared war on the foreign powers.

President McKinley and his foreign policy advisors crafted America’s response to the Boxer Rebellion. The administration preferred the United States to act independently, but circumstances soon prodded McKinley to order the American military commander in China, Rear Admiral Louis Kempff, to “act in concurrence with other powers so as to protect all American interests.” In late June 1900, McKinley transferred 2500 American soldiers from the Philippines to China. The troop dispatch sparked criticism from American (mainly Democratic) politicians and editors who charged the president with imperialism and exceeding his constitutional authority. McKinley believed a president’s constitutional war powers granted him such authority.

American soldiers were among the 20,000 foreign troops who ended the Boxer’s siege of Peking on August 14, 1900. McKinley and Hay issued the Second Open Door Note to “preserve Chinese territorial and administrative entity, protect all rights guaranteed to friendly powers by treaty and international law, and safeguard for the world the principle of equal and impartial trade with all parts of the Chinese Empire.” Its idealistic rhetoric made overt disagreement by domestic and foreign interests difficult, but its implementation was far more problematic. The Boxer Rebellion had undermined the prestige of the Ch’ing administration, and China initiated a series of reforms in 1901. However, the foreign presence and influence in the country continued for decades.