Look carefully at both images. The one on the left is a painting of five pony riders in front of the Patee House in St. Joseph, Missouri. The other is a black and white photograph of the Hollenberg Station in Kansas, where Pony Express riders dropped off mail and picked up fresh horses to continue the journey to Sacramento, California.
Based on what you see, what kind of sources are these two images - primary or secondary?
What date was each source created?