“All US law emanates from the Constitution, much in the same manner as all Commonlaw emanates from the Magna Carta”
I strenuously dispute both points, as English and American law most definitely precedes said documents. Perhaps it is true that English constitutional law emanates from the Magna Carta, but common law goes back to time out of mind. Technically defined as predating 1189, or the start of Richard the Lionheart’s reign, “time immemorial” literally stretches all the way back to the Dark Ages of barbarian Germany. That’s how old English law is.
It may be permissible to say that all U.S. law emanates from the Constitution, as of course there was no U.S. before the Constitution. Anyway, the point is though you are free to define the Constitution as “the Constitution,” to the rest of us it is law (or a series of laws, if you will), just like the Magna Carta is law. I’m not sure why you’ve never come across this basic definition.
“I strenuously dispute both points”
To be clear, I retreated on the first point. At first I thought the implication was that “All U.S. law” meant all American law. However, as I indicated, if you were speaking narrowly and really meant U.S. (i.e. federal) law, fine.