Not only did reservists raid British commerce on the high seas, but they also outfitted a fleet of barges called the Chesapeake Bay Flotilla in an effort to defend that vital body of water against British invasion. Though overwhelmed by an enemy superior in numbers, these men, most recruited from Baltimore, continued to wage war on land, joining in the defense of Washington, D.C. Having fought against a foreign power, naval reservists faced a much different struggle with the outbreak of the Civil War, which divided a navy and a nation. Within days of the attack, President Abraham Lincoln authorized an increase in the personnel levels of the Navy, which assumed an important role in the strategy to defeat the Confederacy with a blockade of the South and a campaign to secure control of the Mississippi River. By war's end the Navy had grown from a force numbering 9,942 in 1860 to one manned by 58,296 sailors. A total of 101,207 men from twenty-one states enlisted during the war and volunteers were present during some of the storied naval engagements of the American Civil War, including serving in "Monitor" during her battle with CSS "Virginia" and the daring mission to destroy the Confederate ironclad CSS "Albermarle". The latter action resulted in the awarding of the Medal of Honor to six reserve enlisted men. With the lack of any major threat to the United States in the post-Civil War years, the U.S. Navy took on the appearance and missions of the force it had in 1860. Then came publication of naval theorist Captain Alfred Thayer Mahan's landmark study "The Influence of Sea Power Upon History", which in part prompted a modernization of the U.S. fleet and brought some of the first calls for an organized naval reserve to help man these more advanced ships. In the meantime, state naval militias represented the Navy's manpower reserve, demonstrating their capabilities during the Spanish–American War in which they assisted in coastal defense and served aboard ship. Militiamen from Massachusetts, New York, Michigan, and Maryland manned four auxiliary cruisers—"Prairie", "Yankee", "Yosemite", and "Dixie"—seeing action off Cuba. All told, some 263 officers and 3,832 enlisted men of various state naval militias answered the call to arms. As successful as the state naval militias were in the Spanish–American War, which made the United States a world power, events unfolding in Europe following the turn of the century demonstrated that a modern war at sea required a federal naval reserve force.