Sherman's army went through South Carolina, but occupied only a small part of it. The war was about lost by then.
SC contributed about 36 regiments to the Confederate army, out of a total of 764. SC did not have much in the way of heavy industry. The port of Charleston was the no. 2 blockade running haven (behind Wilmington, NC) but by 1865 the blockade had largely shut down blockade running there. SC railroads did provide a link between VA and the lower South. Sherman destroyed most of these rail connections.