While the German Budget Committee was thus occupied a new and startling turn was given to the situation by the unheralded appearance at Newport, R. I., on October 7, 1916, of a German submarine, the _U-53_. Rising out of the water in the afternoon, it remained long enough for its captain to deliver a missive for Count von Bernstorff, the German Ambassador, pay a call on Admiral Knight, the American commander there, ask for news of the missing _Bremen_, and obtain a sheaf of New York newspapers for information regarding Allied shipping. Then it left the port, whither it had been piloted, and disappeared under the waves. The visit, standing by itself, was an interesting episode; but it proved to be much more than a mere social call.
The next day revealed the real object of the submarine's presence in American waters. Off Nantucket it appeared in its true guise as a raider of shipping and sank five vessels--three British, one Dutch, and one Norwegian. Having thus brought the submarine war to the very threshold of the United States, causing a reign of terror among held-up shipping along the Atlantic seaboard--a state of mind which, while it lasted, meant a virtual blockade of American ports--it disappeared and was not again heard of.
There was no doubt that the exploits of the _U-53_ were intended as a demonstration to test American feeling as to whether Germany could attack on this side of the water munition and other vessels bound for Allied ports. It appeared a bold attempt to create a new precedent by overriding one laid down in 1870 by President Grant, who ruled that American waters must not be used by other nations for belligerent purposes. Outside the three-mile limit, however, German submarines could operate with the same impunity as in the Arctic Ocean, so long as they observed the requirement of giving warning and allowing people on board the intercepted vessels time to save their lives. But the manifest point was that the waters outside the three-mile limit were contiguous to the American coast, and provided highways for American shipping, coastwise and foreign. The proximity of German submarines, even though they confined their attention to Allied shipping to and from American ports, constituted too great a menace to the free movement of the American mercantile marine.