I purchased a book titled "Our Living Constitution THEN AND NOW", written by Jerry Aten. Not realizing that it was for Grade 5-8. But as it turns out I think it is great in how it is presented and since I am a "mature" person who has been out of school for 63 years, well, you know.
To put things into proper historical perspective, the book begins with a study of the Declaration of Independence. The book says that "when students become aware of the difficulty the colonies had in gaining their freedom, they will have a greater appreciation of the Constitution."
The original words of the Declaration of Independence is in the left-hand column and right-handed column is a more easily understood explanation.
I purchased the book on https://www.thriftbooks.com/ at a very reasonable (cheap) price. It was used but in great shape.