<Li> August 14 - The last battle of the Spanish - American War occurs off Caibarién, Cuba, when the armed supply ship USS Mangrove fires on two Spanish Navy gunboats . The Spanish surrender, and explain that an armistice has been signed . </Li> <Ul> <Li> September 13 - The Spanish national legislature, the Cortes, approves the Protocol of Peace by a vote of 161 to 48 . But many deputies abstain, indicating a deep feeling within the Cortes that the war should continue to be prosecuted . </Li> <Li> September 15 - The Malolos Congress, the assembly of the revolutionary government of the Philippines, convenes in Malolos, Philippines . It ratifies Aguinaldo's declaration of independence, and begins drafting a constitution for an independent Republic of the Philippines . </Li> <Li> September 26 - The War Department Investigating Commission (also known as the "Dodge Commission" after its chairman, Major General (ret .) Grenville M. Dodge) begins investigating the conduct of the U.S. Department of War during the Spanish--American conflict . Vivid testimony by Major General Nelson A. Miles on December 21 about chemically adulterated beef bought by the department to feed soldiers in the field (the "United States Army beef scandal") leads to public outrage . The final report, issued on February 9, 1899, exonerates the War Department but subtly implies that Secretary of War Alger was an inefficient if not incompetent manager . Alger denies the implication, but on July 19, 1899, he resigns (effective August 1). </Li> </Ul> <Li> September 13 - The Spanish national legislature, the Cortes, approves the Protocol of Peace by a vote of 161 to 48 . But many deputies abstain, indicating a deep feeling within the Cortes that the war should continue to be prosecuted . </Li> <Li> September 15 - The Malolos Congress, the assembly of the revolutionary government of the Philippines, convenes in Malolos, Philippines . It ratifies Aguinaldo's declaration of independence, and begins drafting a constitution for an independent Republic of the Philippines . </Li>

Which event contributed to the beginning of the spanish american war