Robert E. Lee had a long and illustrious military career with the United States before he resigned his commission as Commandant at West Point to join his home state in the Confederacy. He knew from the outset that the Confederate States of America (CSA) could not win against the United States of America (USA) or Northern States. He was even offered command of the northern forces by President Lincoln, but could not force himself to bear arms against his fellow Virginians.
He loved his troops, admired their bravery, and (with one exception) never wasted them. To a man they would all die for Bobby Lee. When Richmond was finally taken, he made the difficult decision to end the war after four years of fighting against superior forces who were better trained, better equipped and better fed. He'd lost his own home, most of his own wealth, and suffered his own hardships during the course of the war and never complained. After the war he accepted a post at William college and died 5 years later. He was mourned by both North and South. The college was renamed William and Lee.
Stonewall Jackson was a Bible-thumping soldier of God who fought like hell and his men followed him. He never fought on a Sunday. He got the nickname "Stonewall" at the first battle in the war when his men stood fast while other Confederates were running. One officer yelled at his men to look at Jackson's command because they were standing like a stone wall. He had several brilliant military victories to his credit, but was killed in a friendly fire incident. A sentry mistook him and his staff for a company of Yankees and sounded the alarm.
Ulysses S. Grant has the distinction of graduating in the same class of West Point as Robert E. Lee, but Lee was at the top of the class with not one demerit and Grant was dead last. Grant was an alcoholic, a devoted family man, and a terrible business man. The only thing he was good at was war which he considered a bloody business to be ended as quickly as possible. He was the bulldog that wouldn't let Bobby Lee rest. He was always on the move and he fought anyway he could to bring the war to a close. If that meant burning farms and plantations so the Rebel Army would starve, so be it. If it meant ordering Sherman to march through the heart of the South, burning and tearing up railroads, that was just what had to be done. The only battle he really regretted fighting as he did was Cold Harbor.
After the war was done, he took Lee's surrender with dignity and let Lee keep his. Later he was elected President but had the same bad business sense in that post as he had throughout most of his life.