The effect of the news on the Liverpool Exchange it is needless to describe. By the scratch of a foreign pen a blow that was without precedent was struck at the chief trade of the port. So prodigious indeed was this first act of war that for some time there was a doubt whether the Neutral Powers would recognise it. Only five years before the Powers assembled at Paris to wind up the Russian war had by solemn agreement declared, as the final and universal law of nations, that blockades to be binding must be effective; that is to say, that all the ports declared to be blockaded must be actually invested, or at least so closely watched by a cruising squadron that no ship can attempt to leave or enter without manifest danger of capture. Now, as the seaboard of the Seceding States extended from the river Potomac in Virginia, above Cape Hatteras, down to the Rio Grande (the southern frontier of Texas), the coast-line which the Federal Government had to watch effectively was some 3000 miles in length. It was studded, moreover, at wide intervals with ten or a dozen ports of first-rate importance. The total fleet of the United States when the war broke out consisted of less than 150 vessels, of which fully one-third were quite unserviceable. About forty had crews; the rest were out of commission, and of these ten or eleven of the best were lying at the Norfolk Navy Yard and fell into the hands of the Confederates. From these figures it will be seen, therefore, how impossible it was at first to maintain the blockade which the Northerners had declared, and how ineffectual it must be, seeing the length of coast-line to be watched. With their usual energy, however, the Northerners set to work to increase their fleet; within very few weeks over 150 vessels had been purchased and equipped for sea, and more than fifty ironclads and gunboats laid down and rapidly pushed forward towards completion. In addition to these a large number of river craft were requisitioned and protected by bullet-proof iron for service on the rivers; but even with these vigorous measures the blockade was anything but effective during the first eighteen months or two years of the war. But the Northerners steadily and by almost superhuman efforts increased their fleet, and at the beginning of 1865 had so far succeeded that they possessed a fleet of nearly 700 vessels, of which some 150 were employed upon the blockade of Wilmington and Charleston alone, and patrolling their adjacent waters.