In a war of attrition, the outcome favors the side with the larger economy and population. The North had more industry and a larger population.
The South had some prominent generals who stood out for their leadership. The plantation system may have helped groom these men for leadership of large formations. The rest of Southern society was not right for prepping middle rank officers and there were not enough plantations to groom more than a handful of men capable of generalship. Most Southerners who were the sons of plantation owners had no aptitude or interest in being in the military. The few with the aptitude and the opportunity ended up standing out when the war came.
(Not defending the plantation system. Slavery is abhorrent.)
Good point Bill. But I doubt the plantation system produced few good officers. It was not the kind system to provide leadership that a modern war demanded. In fact I doubt the plantation system provided one whit of benefit to the South. I am a Southern boy and love my Confederate heroes but when Sherman marched trough my native state of Georgia, wrecking and burning everything is sight-he was doing the place a favor. The system had to be dismantled.
I am not so sure about that. Most of even Lee's lower generals were lawyers and politicians. Many did fight in the Mexican war which may be important in the early years. The South was agrarian and Jeffersonian in its policies (funny how Jefferson's party was called Republican at the time ). They liked the Mexican war and wanted to get more land to expand into so more of them volunteered to fight and more of their volunteer leaders got experience down there. It helped that the Texans were mostly from the South and that the South was a lot closer to the fight than, say, Vermont.
This was the early middle of the 19th century and not too far away from the Revolution or the Napoleonic wars. Back then in the 18th century, it was cultural that the comfortable classes contribute leaders; their children were raised up in this environment of privilege. These were people who had no other productive function in society, and it was accepted that they would become either Clerics or Officers. IMHO the South was much of the same mind and cultural background; they had more children of privilege to fill out the early leadership slots. They did fine till the Northern lawyers and politicians got their equivalent of Mexican war experience.
It is possible that the first corner could have been turned earlier but for political pressures. Davis was an officious administrator of the type that puts the modern EPA to shame, but nonetheless he recognized the value of experience. With junior officers this was helpful, but with senior officers who collided with his self-appointed military brilliance, it was fatal. His commanders had to laud his greatness and bow to his authority.
Lincoln, OTOH, spread out BG commissions on the basis of demographics. He wasn't overtly political, but a State would get BG commissions in proportion to their Electoral College representation. The choice would fall on the representatives of the respective States. And so Washburne picks U.S.Grant to become a BG. Lincoln was not military and as soon as a commander came up that he could work with, his hands came off.
It is a matter of moving perspective: with a relatively static source, from a small population, on the one hand, and a relatively dynamic source, from a much larger population, on the other.