Yes - which system do you think America uses?Well it isn't an "either/or" answer.
There's Constitutional Law, from the U.S. Constitution and State Constitutions.
There's statutes and ordinances on the federal, state, or local levels.
There's common law, that being the concept of precedence.
And there's administrative law at the federal, state, and local level.
So it's a little hard to say America's legal "system" is exactly one thing or the other. It's a combination of several things and pretty unique to America.