Both Spain and the United States hastily purchased, in the last days of peace, a few vessels, but not enough seriously to affect their relative strength. Both also drew upon their own merchant marines. Spain added 18 medium-sized vessels to her navy; the United States added in all 123, most of which were small and used for scouting purposes. The largest and most efficient of these additional American ships were the subsidized St. Paul, St. Louis, New York, and Paris of the American line, of which the last two, renamed the Harvard and Yale, proved to be of great service. It was characteristic of American conditions that 28 were private yachts, of which the Mayflower was the most notable. To man these new ships, the personnel of the American Navy was increased from 13,750 to 24,123, of whom a large number were men who had received some training in the naval reserves of the various States. The first duty of the navy was to protect the American coast. In 1885 the War Department had planned and Congress had sanctioned a system of coast defense. Up to 1898, however, only one quarter of the sum considered necessary had been appropriated. Mines and torpedoes were laid at the entrances to American harbors as soon as war broke out, but there was a lack of highpower guns. Rumors of a projected raid by the fast Spanish armored cruisers kept the coast cities in a state of high excitement, and many sought, by petition and political pressure, to compel the Navy Department to detach vessels for their defense. The Naval War Board, however, had to remember that it must protect not only the coast but commerce also, and that the United States was at war not to defend herself but to attack. Cuba was the objective; and Cuba must be cut off from Spain by blockade, and the seas must be made safe for the passage of the American Army. If the navy were to accomplish all these purposes, it must destroy the Spanish Navy. To achieve this end, it would have to work upon the principle of concentration and not dispersion.