This 168-page book offers a thorough study of the historical and literal facts about the Constitution, and a briefer look at modern applications. The publisher recommends it for students in grades 5 to 8, but it is also appropriate for high school level. It covers the entire text of the Constitution, the Bill of Rights, and the remaining amendments, arranging them in two-column fashion with the original text on the left and a "translation" on the right. Interspersed at various points are explanations, activity pages, and research assignments.
With younger students, you might cover selected sections and activities, saving more challenging assignments for older students (e.g., "In the space below cite several examples in today's world where Congress has exercised implied power. Look in newspapers and magazines for additional ideas," or "What is the main essential in a writ of habeas corpus?").
While the perspective is secular, it seems well balanced. You can use the trivial pursuit type game found towards the end of the book to quiz students on their knowledge. The book is reproducible and an answer key is at the back.