Alfred Thayer Mahan was a United States naval officer and historian, whom John Keegan called "the most important American strategist of the nineteenth century." His book The Influence of Sea Power Upon History, 1660–1783 (1890) won immediate recognition, especially in Europe, and with its successor, The Influence of Sea Power Upon the French Revolution and Empire, 1793–1812 (1892), made him world-famous and perhaps the most influential American author of the nineteenth century.
