Alfred T. Mahan was a United States of America navy admiral, strategist and historian. He is considered to be one of the most important American strategist in the 19th century. His most important thesis was that the country with the most powerful navy can have the greatest influence in the world. It is usually called the "sea power" concept. One of his most important books was "The Influence of Sea Power Upon History: 1660 - 1783". It was a history of naval warfare published in 1890. Mahan was born in 1840, and he died in 1914.