Prompt
Create a realistic portrait of John Wesley Powell, an American geologist, explorer, soldier, and professor, from the late 19th century. He should be depicted in a dignified and contemplative pose, possibly with a subtle nod to his adventurous and scientific pursuits. Incorporate elements that reflect his occupations, such as a geological specimen or a map in the background, and his military and academic attire. The style should be reminiscent of classic 19th-century American portraiture, with attention to detail and a sense of gravitas.
