What advantages did the South have over the North during the Civil War?
It would be more nearly correct to state that the military leaders of the South were far superior to those of the North. General Winfield Scott had offered command of Union forces to Robert E. Lee, who declined because his conscience would not let him fight against his native Virginia. Stonewall Jackson was professor of geometry at Virginia Military Institute prior to the war. Gen. Pierre Beauregard was a West Point Graduate who had studied engineering there. It was ironic that he had studied under Gen. Robert Anderson, whom he defeated at the Battle of Fort Sumter. It is noteworthy that the South had only one commander in chief for the duration of the war. The North had several, many of whom were removed by President Lincoln from command.
The South was not more militaristic, but southern men had lived closer to the earth, frequently hunting as a pastime. As a result, they were more experienced with firearms and better marksmen than draftees from the North.
It is doubtful that the South had it more easily strategically. It is more correct to state that since the war was with rare exception fought in the South, the Southern troops had something of a home field advantage. It should be noted that they did in fact invade the North twice, hoping in at least once instance to gain recognition from Europe. Both attempts, at Antietam and Gettysburg failed.
The South had no possibility of winning the war; rather its advantages allowed it to prolong the war which otherwise would have ended much more quickly.
The South had two major advantages.
First, the South was the more militaristic society. Most of the officer corps of the US Army was from the South. People from the South were more likely to grow up riding horses and shooting guns. This made them more likely to be good soldiers.
Second, the South had the easier strategic task in the war. They did not need to invade and defeat the North. Instead, they just had to hold out long enough for the North to get tired of the war and give up.
Of course, neither of these advantages was enough to allow the South to win.