When the US Civil War began, the North had a small ineffectivenavy. This soon rapidly changed. More warships were built to use onrivers and to blockade Southern ports.The South had no navy at allwhen the war began. They were however able to buy some warshipsfrom England and to construct a few warships of their own. TheSouth's navy was bwst used to try to free its ports or to sinkUnion cargo ships.