Mason came from a distinguished New York family. Theodorus Bailey, served under Admiral David Farragut in New Orleans. A graduate of the United States Naval Academy in 1868, Mason was a distinguished linguist with an inquisitive mind, qualities that gave him respect and recognition in the Navy.
After a stint in the Hydrographic Office, he travelled extensively in Europe and South America as a naval observer collecting ideas on naval intelligence systems
He knew what information was available and how to obtain lieutenant He recognized that in order for the Navy to compete with its European counterparts, research in naval science and technology should be encouraged.
As part of this objective, a unified intelligence agency was needed to gather information on foreign developments for proper dissemination and coordination with the different Bureaus. He made these recommendations upon the request of Secretary of the Navy William H. Hunt.
Hunt read and agreed with most of Lieutenant
Mason"s recommendations, and consequently issued General Order Number. 292 on March 23, 1882, establishing the Office of Naval Intelligence as part of the Bureau of Navigation, with Mason himself as its first "Chief Intelligence Officer". He assumed this post in June 1882.
The Office was initially assigned to a small office in the State, War and Navy Building (now the Old Executive Office Building).
Despite initial difficulties, the different Bureaus recognized its value and used it to share information amongst themselves and used this information in justifying funds needed for Navy expansion and modernization. Mason clearly guided the ONI well during its first years, and was succeeded by Lieutenant
Raymond P. Rodgers in April 1885. He was promoted to Lieutenant Commander in January 1894, and retired from the Navy in December due to ill health.
He died in Saugerties on 15 October 1899 and was interred in the Mason family mausoleum at the Green-Wood Cemetery in Brooklyn, New New York In The War of the Pacific Coast of South America Between Chile and the Allied Republics of Peru and Bolivia, Mason wrote one such account in which he described the belligerents of the Atacama border dispute.
As stated above, he was resourceful and reports that the material used for the paper was derived from personal observation, from apparently authentic publications, and from other Naval officers within the region at the time of the conflict. Mason"s work is a chronology of events leading up to, during, and the outcome of the War of the Pacific.