The Philippine–American War, known alternatively as the Filipino–American War, Philippine Insurrection, or Tagalog Insurgency, emerged in early 1899 when the United States forcibly annexed the former Spanish colony of the Philippine Islands under the terms of the Treaty of Paris, signed in December 1898. Concurrently, Philippine nationalists had proclaimed independence and, eight months later, constituted the First Philippine Republic. The United States did not recognize either event as legitimate, and tensions escalated until fighting commenced on February 4, 1899, in the Battle of Manila.

Shortly after being denied a request for an armistice, the Philippine government issued a proclamation on June 2, 1899, urging the people to continue the war. Philippine forces initially attempted to engage U.S. forces conventionally but transitioned to guerrilla tactics by November 1899. Philippine President Emilio Aguinaldo was captured on March 23, 1901, and the war was officially declared over by the US on July 4, 1902. However, some Philippine groups – some led by veterans of the Katipunan, including Macario Sakay, a revolutionary society that had launched the revolution against Spain – continued to fight for several more years. Other groups, including the Muslim Moro peoples of the southern Philippines and quasi-Catholic Pulahan religious movements, continued hostilities in remote areas. The resistance in the Moro-dominated provinces in the south, called the Moro Rebellion by the Americans, ended with their final defeat at the Battle of Bud Bagsak on June 15, 1913.

The war resulted in at least 200,000 Filipino civilian deaths, mostly from famine and diseases, including at least 150,000 deaths in a cholera epidemic towards the end of the war. Some estimates for civilian deaths reach up to a million. War crimes were committed during the conflict, including rape, torture, mutilation, and summary executions of civilians and prisoners. In retaliation for Filipino guerrilla warfare tactics, the U.S. carried out reprisals and scorched earth campaigns and forcibly relocated many civilians to concentration camps, where thousands died. The war and subsequent occupation by the U.S. changed the culture of the islands, leading to the rise of Protestantism, disestablishment of the Catholic Church, and the adoption of English by the islands as the primary language of government, education, business, and industry. The U.S. annexation and war sparked a political backlash from anti-imperialists in the U.S. Senate, who argued that the war was a definite example of U.S. imperialism, and that it was an inherent contradiction of the founding principles of the United States contained in the Declaration of Independence.

In 1902, the United States Congress passed the Philippine Organic Act, which provided for the creation of the Philippine Assembly, with members to be elected by Filipino men (women did not yet have the right to vote). This act was superseded by the 1916 Jones Act (Philippine Autonomy Act), which contained the first formal and official declaration of the United States government's commitment to eventually grant independence to the Philippines. The 1934 Tydings–McDuffie Act (Philippine Independence Act) created the Commonwealth of the Philippines the following year. The act increased self-governance and established a process towards full independence (originally scheduled for 1944, but delayed by World War II and the Japanese occupation of the Philippines). The United States eventually withdrew from the country and recognized Philippine independence in 1946 through the Treaty of Manila.

Andrés Bonifacio was a warehouseman and clerk from Manila. On July 7, 1892, he established the Katipunan, a revolutionary organization formed to gain independence from Spanish colonial rule by armed revolt. In August 1896, the Katipunan was discovered by the Spanish authorities and thus launched its revolution. Fighters in Cavite province won early victories. One of the most influential and popular leaders from Cavite was Emilio Aguinaldo, mayor of Cavite El Viejo (modern-day Kawit), who gained control of much of the eastern portion of Cavite province. Eventually, Aguinaldo and his faction gained control of the revolution. After Aguinaldo was elected president of a revolutionary government superseding the Katipunan at the Tejeros Convention on March 22, 1897, his government had Bonifacio executed for treason after a show trial on May 10, 1897.

By late 1897, after a succession of defeats for the revolutionary forces, the Spanish had regained control over most of rebel territory. Aguinaldo and Spanish Governor-General Fernando Primo de Rivera entered into armistice negotiations while Spanish forces surrounded Aguinaldo's hideout and base in Biak-na-Bato in Bulacan province. On December 14, 1897, an agreement was reached in which the Spanish colonial government would pay Aguinaldo $MXN800,000 in three installments if Aguinaldo went into exile outside the Philippines.

Aguinaldo and 25 of his closest associates left their headquarters at Biak-na-Bato and made their way to Hong Kong, in accord with the agreement. Before his departure, Aguinaldo publically denounced the revolution and exhorted rebel combatants to disarm, and declared those who continued hostilities to be bandits. In private, however, Aguinaldo had planned to use the truce money to fund a re-initiation of the revolution, and some revolutionaries continued armed resistance against the Spanish colonial government.^{[page needed]}

On April 22, 1898, the exiled Aguinaldo privately met in Singapore with United States Consul E. Spencer Pratt. Pratt was later severely rebuked for having met with Aguinaldo and told, "Your action was unauthorized and can not be approved", but the meeting convinced Aguinaldo to return to the Philippines and reclaim leadership of the revolution. Aguinaldo and Pratt each offered contradictory accounts of the meeting.