Hidden away south of the Lincoln Memorial and just steps from the Potomac lies a monument that seems out-of-place on the National Mall. The inventor of the screw propellor may seem like a dull and undeserved choice for memorialization here. However, John Ericsson's achievements were arguably as pivotal to victory in the American Civil War as President Lincoln's leadership. An engineering prodigy from an early age, Ericsson immigrated to the United States where he hoped that his screw propellor would be more well-received in a more open intellectual environment. There, he helped develop the U.S.S. Princeton, which proved to be the most sophisticated warship yet afloat. Later on during the American Civil War, he designed the ironclad U.S.S. Monitor, revolutionizing naval warfare once again. Similar monitor warships were used to ensure naval victory of the Union in the war.…