The influence of the Civil War upon the merchant marine must now have consideration. First of all, the appearance of Confederate privateers upon the ocean at once doubled the rate of insurance on all American merchantmen. Then, when Commander J. D. Bullock, of the Confederate navy, was sent to England to buy iron-clad war-ships with which to raise the blockade of Confederate ports, and was induced to build swift cruisers with which to raid the North's merchant marine, a still heavier blow was struck. In all, the Confederates had 19 cruisers at sea, and they captured 257 merchantmen. The loss of these ships, however, was the smallest part of the injury suffered. The possibility of capture deprived American ships of the opportunity to obtain cargoes, and led to a cessation of building in American shipyards. It led many owners to transfer their vessels to foreign flags. It changed the currents of commerce. Naturally the British merchants took every advantage of their opportunity, as the Americans had done in the troubled days of the war with Napoleon. One might suppose that the demand for naval ships would have given prosperity to the shipyards and engine works, but John Roach testified before the committee mentioned that "out of ten marine engine shops that were in existence in New York at the commencement of the war, his was the only one remaining in existence." Though iron was largely used in the government ships, Nathaniel McKay, the ship-builder, told this committee that "_we have got to have some experience in building iron ships_. We have built but few iron ships, and most of them were failures." Mere mention only of the transfer of American capital from the sea to the shore need be made here. With the depreciated currency there was plenty of opportunity for "wildcat" speculations; for government contracts, and for other kinds of investments more to the taste of honest capitalists. The whole seafaring population spent the war period in acquiring new habits, while the British ship-builders were busy perfecting their arts, and the British merchants were establishing themselves firmly in the trades from which the war drove the Americans.