Lee is a gentleman, a man of honor, and a religious man with no vices and considerable patience. Optimistic and idealistic, he believes his men can do anything. He is soft-spoken and cares about his men, but is willing to use them boldly and lose them for the Cause. He believes deeply in his God and feels God is controlling the course of events.
The Lee in this novel frequently comes across as a near zealot, blindly going forward in spite of the possible better advice of Longstreet and others. While Lee was a strong commander who didn't waver in his decisions, casting him as rigid and obsessed may not be totally accurate. Many essays and books offer logical support and reasons for Lee's decisions here.
Even within this story, Lee struggles with decisions and considers all possibilities before picking a course of action. In fact, throughout this battle, Lee constantly rethinks his plans to offset changes in circumstances, errors made by his commanders, or his orders being disobeyed. He is not rigidly attached to any plan if another will achieve his goal.
Lee is a risk-taker, makes chancy and daring decisions, and even breaks the rules because time is against him. The North can outlast him in men and supplies. Also, his health problems show up in the story and are a reminder that he may not last the war. So he is determined to fight at Gettysburg if at all possible and not retreat.
Virginia is Lee's first priority. For him, Virginia is the Confederacy, and he is involved in this war on the Confederate side only because his home state of Virginia chose to leave the Union. His decisions of where to attack and why are based on his loyalties.
Lee favors offensive Napoleonic warfare tactics and despises defensive strategies. He also despises the use of paid spies. His command style is loose, which is good, as he trusts his men to execute their orders without him micromanaging. It is bad because his complete trust in his men results in disappointments, such as Stuart being out of touch with Lee for several critical days, leaving Lee blind in enemy territory.
Also, an invasion of this sort so far from home, with plans of such grand scale, requires tight control and flawless communication. Lee issues no written orders, some of his orders are confusing, and he never gets all his generals together in one place to coordinate planning. This lack of organization is a downfall, especially with new commanders in place after Jackson's death.
Lee's men hold him in high esteem. They view him as nearly a god and will do anything he asks. Even when the battle fails, his men do not blame him and are ready to fight some more.
Longstreet is important to Lee. He values Longstreet for his strength, experience, and friendship. With the death of Jackson, Lee looks for the company and support of a veteran commander he can depend on.