This is excellent!!! I love it. The reasoning is very solid and the writing is both clear and grammatically correct. Some of your sentences also show a real ability to vary the traditional sentence structure without losing clarity, for instance:"In Linda Sue Park's A Long Walk to Water, the author wrote about two stories, same place, different periods." That last phrase with its parallel structure, "same place, different periods" for emphasis is perfect.
Wonderful use of transitions like "As we know." Nicely written conclusion makes the writing come full circle. Terrific work!