From that time forward two objects engaged Federal attention so far as Charleston was concerned; one of these was to maintain in front of the harbor a blockading squadron strong enough to prevent the entrance and exit of ships. The other was to force the harbor itself, capture its defenses and recover the city to Federal possession. In both of these efforts the Federal operations failed, but in their progress they involved some of the severest and most picturesque battling of the war. The profits of blockade running were so great that English capitalists invested lavish sums in the business as a promising speculation. They built ships of light draft, great power, and a speed greater than that of any vessel in the American navy for the express purpose of carrying on this forbidden traffic. These ships had but little free-board exposed above the water. They were painted a dull sage green, as nearly as possible the color of the sea itself, when looked at from a distance. They were commanded by daring navigators and manned by equally daring crews who stood ready to take any and every risk that might aid in the achievement of ends so profitable as those aimed at in this commerce. And those profits were tempting in an extraordinary degree. With cotton purchasable in the South for a few cents per pound, payable in the enormously depreciated Confederate currency, and salable in England at almost incredibly high prices in gold, and with all forms of English-made goods bearing fabulous prices in the South, it was easily calculable that if a ship could complete one round trip from Nassau to Charleston and back again and then should be lost with all its cargo on a second attempt, there would still remain to the owners a profit of not less than a hundred per cent upon the money invested. As a matter of fact the steamer Minho, and several others of the blockade runners continued until late in the war to make their trips successfully, almost with the regularity of packet boats. They carried into Charleston stores of quinine, opium and other drugs which the Confederate Government stood ready to buy at fabulous prices. They carried clothing also, and shoes and harness, all of which were eagerly purchased at any price that the importers might choose to charge. They carried out of Charleston the cotton to which the markets of the world were otherwise closed, and which could be purchased, therefore, at a price so low as to make its cost an inconsiderable fraction unworthy of consideration. So the blockade running went on.