On April 11, 1900, the U.S. Navy acquired its first submarine, a 53-foot craft designed by Irish immigrant John P. Holland. Propelled by gasoline while on the surface and by electricity when submerged, the Holland served as a blueprint for modern submarine design. By the eve of World War I, Holland and Holland-inspired vessels were a part of large naval fleets throughout the world.
Designs for underwater boats date back to the 1500s. In the nineteenth century, the first truly practical submarines began to appear, with a period of intense development occurring at the end of the century as nations strived to establish their sea power. Seizing upon the latest military technology, the United States used subs in both the War of 1812 and the Civil War. It was not until World War I, however, that submarines emerged as major weapons.