I am sorry, but what am I missing?
The difference between the United States Constitution and the common law. Common law has its roots in history, especially the English common law. There is, howevere, no FEDERAL common law. Common law is a state concept. Under the Erie doctrine, there is no federal common law.
Historical law may have influenced the Framers when they wrote the U.S. Constitution, but the law of the Constitution is found in its text, not in historical precepts. The Constitution says what it says. Federal statutes say what they say. They are not concepts that evolved, they are legislative enactments that can only be interpreted from the text.
AAAGHHHHH!!! Erie Doctrine !!!!! (runs away screaming)