On September 15, 1898, La Republica Filipina, an independent and nationalist newspaper founded by Pedro Paterno, was published in Mandaluyong.

Significant Events in September in Filipino History
Jose Yao Campos, also known by his Chinese name Yao Cho Liat, was a Filipino-Chinese businessman whose remarkable journey as one of the Philippines' most influential taipans left an indelible mark on the nation's pharmaceutical and business landscape. As the founder of United Laboratories (Unilab), Campos transformed a small corner drugstore into the country's largest drug-manufacturing company, earning him the title "Father of the Philippine Pharmaceutical Industry". His life story is one of resilience, strategic vision, and quiet philanthropy, though not without controversy due to his association with former President Ferdinand Marcos.
On September 16, 1635, Father Pedro Chirino, author of one of the first history books of the Philippines, died in Manila. Chirino a Jesuit missionary, wrote the Relacion de las Islas Filipinas in 1603. Having passed the censorship of vice-provincial Luis de la Puente in Villadolid, it was published in Rome in 1604.
On September 16, 1807, the Basi Revolt, also known as the Ambaristo Revolt, erupted in Piddig, Ilocos Norte. This significant event in Philippine history was a direct response to the Spanish colonial government's monopoly on the production and trade of basi, a traditional sugarcane wine deeply rooted in Ilocano culture.
Francisco Makabulos y Soliman, also spelled Francisco Macabulos, was a prominent Filipino revolutionary general, playwright, poet, and politician who played a key role in the Philippine Revolution against Spain and the subsequent Philippine-American War. Born on September 17, 1871, in La Paz, Tarlac, he was the son of Alejandro Makabulos from Lubao, Pampanga, and Gregoria Soliman. Makabulos is remembered as one of Tarlac's foremost patriots, often hailed as the province's liberator and a poet-warlord who combined literary talent with military strategy.
On September 17, 1935, the election for the first officials of the Philippine Commonwealth was held, with Manuel L. Quezon winning the presidency.
On September 19, 1914, Simplicia "Nena" Laconico Saguil was born in Santa Cruz, Laguna, to Epifanio Saguil and Remedios Laconico. Her father was a private physician to Commonwealth President, Manuel L. Quezon. She was one of ten children.
On September 19, 1947, Emmet O'Neal, accompanied by his wife Glessie and their daughters, Lydia Wright and Mary Hamilton, sailed from San Francisco August 22, 1947 on the S.S. President Monroe, arrived in Manila to assume the post of United States Ambassador Extraordinary and Plenipotentiary to the Republic of the Philippines.
On September 19, 1829, Joaquin Pardo de Tavera, reformist, liberal-minded lawyer and an early supporter of the Filipino cause during the Spanish colonization, was born in San Roque, Cavite to Julian Pardo de Tavera who was originally from Toledo, Spain and Juana Maria Gomez also of Spanish descent.