"Now therefore I, Abraham Lincoln, President of the United States...have further deemed it advisable to set on foot a blockade of the ports within the States aforesaid, in pursuance of the laws of the United States and of the Law of Nations in such casem provided. For this purpose a competent force will be posted so as to prevent entrance and exit of vessels from the ports aforesaid. If, therefore, with a view to violate such blockade, a vessel shall approach or shall attempt to leave any of the said ports, she will be duly warned by the commander of one of the blockading vessels, who will endorse on her register the fact and date of such warning, and if the same vessel shall again attempt to enter or leave the blockaded port, she will be captured, and sent to the nearest convenient port for such proceedings against her, and her cargo as prize, as may he deemed advisable." - Abraham Lincoln
The goal for the blockades was to undermine the South's ability to wage war, engage international and intercoastal trade as well as destroying its economy. At first, the blockade posed little threat to the South, for the Northern Navy didn't quite possess the resources to make it effective. The North only had ninety wooden ships to commence their blockade, half of which were in commission when the war broke out. Within months, the construction of new blockading ships was on its way and the Northern blockades finally began to reach effectiveness, within a year cutting off several Southern harbors from the outside world. At first, the South had no war ships at all but soon merchant ships were requisitioned and armed. the mainstay of the blockading fleet was gunboats and sloops. Expected to cope with ships of their own group, they did this while the raiders and privateers preyed on the enemy's merchant marine. Privateers were privately owned vessels operating with the agreement of their own government, and made their profit from vessels captured and sold in a prize court set up ashore. Then there were cruisers, who were mainly used to patrol the ocean highways and hunt down the riders. In importance they ranked close to the ironclads but were not suited to fight ironclads, which had superior protection. Cruisers also acted as blockaders along the coasts and deeper rivers. Most boats were derived from what used to be Ferry Boats and Fishing Boats. China and upholstered furniture were tossed aboard as they were converted into warships. To compensate for a lack of naval guns, army field pieces were snatched from forts and wheeled onto tarred deckings, then lashed down. Then, someone got the crazy idea to nail iron plating onto the ship's wooden surfaces. Who would have known that that act alone would have revolutionized naval ships more than anything had before.