Final answer:
The author in question is James Fenimore Cooper, known for his historical novel 'The Last of the Mohicans'.
Step-by-step explanation:
The last name of the author who wrote of the Solemn Friend of Widows and Orphans, the little Indians, and the Phantom is James Fenimore Cooper. He is known for his historical novel, The Last of the Mohicans, part of the Leatherstocking series, which includes a portrayal of Native Americans during the French and Indian War. Cooper's works are significant in early American literature for the romanticized portrayal of Native cultures and the era's prevalent themes of exploration and frontier life.