This is the premiere site for important documents relevant to the Philippine-American War. Full texts to treaties such as the Protocol of Peace (1898), the Treaty of Paris, and the Bates Treaty and of proclamations and manifestos such as Agoncillo's protest against the Treaty of Paris, McKinley's Benevolent Assimilation Proclamation, Gen. Otis' claim of sovereignty proclamation, Gen. Aguinaldo's protest to the previous, the U.S. offer of autonomy, Paterno's proclamation of war, Aguinaldo's proclamation of surrender, and Pres. Roosevelt's proclamation ending the "insurrection".
Full text of the capitulation or surrender of Manila by Spanish authorities to the Americans (14 Aug 1898).
Full text of the proclamation of occupation of Manila by Gen. Wesley Merritt (14 Aug 1898).
Scroll near the middle (or search for "grayson") for the eyewitness account of Priv. William Grayson of that fateful night of 4 Feb 1899.
Search for "Richard Henry Little" to find the full text of the account of the discovery of the body of Gen. Gregorio del Pilar. This is slightly different from what is quoted in Torn and Frayed above. If you cannot access the main site, use the Internet Archive: http://web.archive.org/web/20020104123637/www.bakbakan.com/junglep/jp-1.html
Still another version of the same account by Richard Henry Little. From Google Books.
Newspaper account of the Battle of Tirad Pass, published June 4, 1900. Gen. del Pilar here is mistaken for Gen. Aguinaldo. From the New York Times archive.
English Wikipedia article on the Lodge Committee, which investigated alleged war crimes of American soldiers during the Philippine-American War. The article is heavily referenced to Wikisource.