January 4 – U.S. President William McKinley's declaration of December 21, 1898, proclaiming a policy of benevolent assimilation of the Philippines as a United States territory, is announced in Manila by the U.S. commander, General Elwell Otis, angering independence activists who had fought against Spanish rule.
January 16 – Eduardo Calceta is appointed as Chief of the Army (Jefe General) of the rebel Philippine Republic army by Emilio Aguinaldo.[1]
February 4–5 – 12,000 American troops advanced through 2 miles of Filipino front at the Battle of Manila. It was the first and largest battle of the Philippine–American War, resulting to 60 American dead and 2,000 Filipino dead.
February 10 – A brigade of American soldiers attacked Filipino troops after 3 hours of artillery bombardment at the Battle of Caloocan. The capture of Caloocan left American forces in control of the southern terminus of the Manila to Dagupan railway, along with five engines, fifty passenger coaches, and a hundred freight cars.[2]
March
March 7 – The Provisional Law on the Judiciary is issued to provide for the selection of a Chief Justice.
March 27 – American troops marched through Marilao River while being fired upon by Filipino troops on the opposite bank.
April 23 – The Battle of Quingua was fought between Filipino troops led by General Gregorio del Pilar and American troops under Major J. Franklin Bell. There was a short Filipino victory until reinforcements sealed eventual American victory.
April 30 – The U.S. establishes a protectorate over the Republic of Negros, a semi-independent government for Negros Island, separate from the rest of the Philippine Islands. The Republic exists until its annexation to the rest of the U.S. territory on April 20, 1901.
May
May 6 – Local elections were held for provincial and municipal posts throughout the Philippine Archipelago under the American occupation.
May 11 – The country adopts PHT as its standard time at exactly 12:00a.m., prior to the adoption, each location in the country observed its own solar mean time.[3]
May 16 – The last Spaniards remaining in the Philippine Islands, after the cession to the U.S., depart from the island of Basilan.
May 23 – Major General Henry Ware Lawton and his troops arrive in Manolos, capital of the First Philippine Republic, after a 120-mile march in 20 days that captured 28 towns with a loss of only six men.[4]
May 28 – General Vicente Álvarez forms the short-lived Republic of Zamboanga on a peninsula on the island of Mindanao. The nation exists until 1903 when it is consolidated by the U.S. to the rest of the Philippine territory.
May 29 – The Spanish system of courts, closed since the American occupation began, is revived under U.S. sovereignty and regulation.[4]
October 1 – Felipe Agoncillo, dispatched by the Philippine Revolutionary government to lobby for independence, meets U.S. President McKinley, in Washington and his attempt to be part of peace talks between the United States and Spain is rejected.[6]
November 13 – President Aguinaldo, after a conference in Bayambang, Pangasinan, declared guerrilla warfare in the continued Filipino struggle against American occupation.[7]
December
December 2 – A 60-man rear guard action led by General Gregorio del Pilar fought 500 American troops who were pursuing President Aguinaldo in his flight to land's end.
December 11 – Filipino General Tierona surrenders the province of Cagayan to U.S. Navy Captain McCalla of the USS Newark.
Gregg Jones, Honor in the Dust: Theodore Roosevelt, War in the Philippines, and the Rise and Fall of America's Imperial Dream (Penguin Publishing Group, 2012) p. 108