Hillsdale College is offering a 10-week, on-line course titled "Constitution 101: The Meaning and History of the Constitution." Material such as this offering can be quite helpful.
The lectures are usually posted and can be accessed that day or week or more.
Check this page for link to the Introduction to the Constitution series:
There is a lot that was not taught in civics classes. Where else can one get a college level class on this topic that is easy to follow and takes only about an hour per week? Try it.