The Coast Artillery began its history during the Spanish American War. The history is traced in the following chronology.
February 15, 1898 – Battleship MAINE sinks in Havana harbor after a disasterous explosion.
March, 1898 - The Army forms the 6th Artillery Regiment at Ft. McHenry, Baltimore, Maryland (except for Battery O and one other battery that are formed a year later).
April, 25, 1898 – The United States declares war on Spain.
July, 1898 - Two batteries of the 6th Artillery ship from San Francisco to the Philippines, arriving in August. Battery D went to Manila, Battery G to Iloilo, on the Island of Panay.
August 13, 1898 – Manila Falls; Armistice declared and fighting between the U.S. and Spain ends.
December 10, 1898 – Spanish American War ends with the signing of the Treaty of Paris.
February 4, 1899 – The Cuban American War begins.
March 1899 - Battery O, 6th Artillery is formed in the United States; Battery D, 6th Artillery participates in the attack and capture of Malabon.
April 1899 - Battery O, together with most of the rest of the 6th Artillery Regiment, steamss for the Philippines, arriving in May 1899 (i.e., after the battle of Malabon.)
Battery O remains in the Manila area. By September, 1900 the unit is located at Santa Lucia, near Manila.
1901 - the 6th Artillery Regiment is broken into independent companies. Battery O was redesignated the 71st Company, Coast Artillery Corps, and stationed at Ft. Santiago, near Manila.