The latest lesson published by TED-Ed explains to students why the Bill of Rights was added to the US Constitution. In the lesson students learn about the positions of Federalists and Anti-Federalists, which states pushed for a Bill of Rights, and why the Bill of Rights was added as a set of amendments to the Constitution rather than rewriting the Constitution.
Why Wasn’t the Bill of Rights Originally in the Constitution? is concise and covers the basics of the arguments of Federalists and Anti-Federalists. The video is a good introduction to those arguments, but a little too basic for a high school classroom.