United States in World War I 11 approximately 10,000 fresh soldiers were arriving in France daily. In 1917, Congress gave US citizenship to Puerto Ricans when they were drafted to participate in World War I, as part of the Jones Act. In the end, Germany miscalculated the United States' influence on the outcome of the conflict, believing it would be many more months before US troops would arrive and overestimating the effectiveness of U-boats in slowing the American buildup. The United States Navy sent a battleship group to Scapa Flow to join with the British Grand Fleet, destroyers to Queenstown, Ireland and submarines to help guard
Naval warfare of World War I Fleet defended the port of Sulina throughout the second half of 1916, causing the sinking of one German submarine. Its minelayer also defended the Danube Delta from inland, leading to the sinking of one Austro-Hungarian Danube monitor. (See also Romanian Black Sea Fleet during World War I) When Bulgaria entered World War I in 1915, its navy consisted mainly of a French-built torpedo gunboat called "Nadezhda" and six torpedo boats. It mainly engaged in mine warfare actions in the Black Sea against the Russian Black Sea Fleet and allowed the Germans to station two U-boats at Varna, one of which