Who is Lieutenant Allen Hall from Behind Rebel Lines: The Incredible Story of Emma Edmonds, Civil War Spy and what is their importance?

When Emma disguised herself as Bridget O'Shea, she took shelter in an old, abandoned house. Also present in the house was a Confederate lieutenant by the name of Allen Hall. Hall was dying of typhoid fever, but before he died, he asked Emma to see that his pocket watch was given to his major. Emma carried out his last wish.