How does Shaara describe Lee viewing his defeated army from his horse in the novel, The Last Full Measure?

Shaara describes General Robert E. Lee, as he sits astride on his white horse Traveler on a high bluff overlooking the Potomac River. While Lee observes his defeated army making its retreat from the Battle of Gettysburg, the hard rain and the swollen Potomac river sets the mood of despair and defeat. The occasional cannon and musket fire lends an air of desperation.