Why the South lost the war

Not an expert, academic opinion, but merely some observations. Armies win battles and campaigns, but factories win wars. The North had a leg up just on that fact alone. The longer the war was prolonged, the less likely that the South could hope even to sue for peace. The materiel production and population base was in the North, and that was hard for the South to overcome. Perhaps if Stonewall had been allowed to go on up the Valley early in the war, it might have scared the North so much that they would have struck a deal, but the South had their own problems protecting Richmond, so that would never have been allowed.

The South had perhaps better officers early in the war, but they could not replace them, and the code of those days required that officers place themselves out in front and exposed to fire.

And Stonewall was killed. That fact alone changed the whole course of the war.