"The Gulf and Inland Waters" by A. T. Mahan is a historical book about naval actions in the American Civil War. It's mainly about the fights that happened in the Gulf of Mexico and the Mississippi River. The Union Navy wanted to control these waters because they were very important for moving soldiers and supplies. The author explains how the Union had to both control the rivers and block the Confederate coast. The book talks about important naval officers and goes into detail about early battles, different kinds of ships, and the war plans used. It shows how important these sea battles were for how the Civil War turned out.

The Gulf and Inland Waters The Navy in the Civil War. Volume 3.
By A. T. (Alfred Thayer) Mahan
During the American Civil War, a nation's naval forces vie for control of vital waterways, facing strategic challenges and intense battles that ultimately shape the conflict's outcome.
Summary
About the AuthorAlfred Thayer Mahan was a United States naval officer and historian, whom John Keegan called "the most important American strategist of the nineteenth century." His 1890 book The Influence of Sea Power Upon History, 1660β1783 won immediate recognition, especially in Europe, and with the publication of its 1892 successor, The Influence of Sea Power Upon the French Revolution and Empire, 1793β1812, he affirmed his status as a globally-known and regarded military strategist, historian, and theorist. Mahan's works encouraged the development of large capital ships β eventually leading to dreadnought battleships β as he was an advocate of the 'decisive battle' and of naval blockades. Critics, however, charged him with failing to adequately explain the rise of largely land-based empires, such as the German or Ottoman Empires, though Mahan did accurately predict both empires' defeats in World War I. Mahan directly influenced the dominant interwar period and World War II-era Japanese naval doctrine of the "decisive battle doctrine" , and he became a "household name" in Germany. He also promoted American control over Hawaii though he was "lukewarm" in regards to American imperialism in general. Four U.S. Navy ships have borne his name, as well as various buildings and roads; and his works are still read, discussed, and debated in military, historical, and scholarly circles.
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 1890 book The Influence of Sea Power Upon History, 1660β1783 won immediate recognition, especially in Europe, and with the publication of its 1892 successor, The Influence of Sea Power Upon the French Revolution and Empire, 1793β1812, he affirmed his status as a globally-known and regarded military strategist, historian, and theorist. Mahan's works encouraged the development of large capital ships β eventually leading to dreadnought battleships β as he was an advocate of the 'decisive battle' and of naval blockades. Critics, however, charged him with failing to adequately explain the rise of largely land-based empires, such as the German or Ottoman Empires, though Mahan did accurately predict both empires' defeats in World War I. Mahan directly influenced the dominant interwar period and World War II-era Japanese naval doctrine of the "decisive battle doctrine" , and he became a "household name" in Germany. He also promoted American control over Hawaii though he was "lukewarm" in regards to American imperialism in general. Four U.S. Navy ships have borne his name, as well as various buildings and roads; and his works are still read, discussed, and debated in military, historical, and scholarly circles.