Who is Major Stuart from Wieland; and Memoirs of Carwin the Biloquist and what is their importance?

Major Stuart is Louisa's father. He discovers his daughter while traveling the colonies. She had previously been taken from him by her mother. Stuart leaves his daughter in Wieland's care while he finishes his travels. Unfortunately, he returns too late to retrieve her, as she has already been murdered. We later learn that Stuart is murdered shortly before participating in a duel with the man who seduced his wife.