Been doing some reading; don't have a specific, single reference for these tidbits:
Most Southern states began building up their militias in 1859, but by secession time they were still poorly equipped. After secession, they took over the Federal arsenals, depots, and forts. A few of the Federals were able to destroy their stocks, but most were just forced to leave it behind. The US arsenal at Harper's Ferry was raided for manufacturing equipment, which was taken to Richmond. The South had one large powder-manufacturing plant at Augusta, Ga, and other smaller ones.
Bottom Line: The South had only enough supplies for about a year of warfare at any given time, and less than that, most of the time. sometimes it was just enough for "one more battle". They captured quite a bit from the Union defeat at Manassas. But they did not have the supplies for a protracted offensive war. The best they could do was to try to hold out long enough for the North to get tired of fighting....that didn't work. The push into the supply depots in Pennsylvania in 1863 was to capture enough stocks to keep going AND to demoralize the North, but neither idea worked.
The only long-range "raid" on the North was the St Albans, Vt, thing in Oct 1864.
The fight at Gettysburg was definitely the turning point of the war. From then on, it was downhill all the way.