The foundation of the US legal system is English Common Law not Roman Law. The only places where this is not true is Lousiana where law derives from the Napoleonic Code, and property law in the West, water rights and that sort of thing which has a strong Spanish influence.
Yes there is an overly of law French, from the Normans on Anglo Saxon law, but our rights and traditions are very distinct from any roman country.
Amusingly, South Africa, which was founded on Roman Dutch Law has moved sharply towards a strong English Common Law influence.
From “Life of Brian”
REG: They’ve bled us white, the bastards. They’ve taken everything we had, and not just from us, from our fathers, and from our fathers’ fathers.
LORETTA: And from our fathers’ fathers’ fathers.
REG: Yeah.
LORETTA: And from our fathers’ fathers’ fathers’ fathers.
REG: Yeah. All right, Stan. Don’t labour the point. And what have they ever given us in return?!
XERXES: The aquaduct?
REG: What?
XERXES: The aquaduct
REG: Oh. Yeah, yeah. They did give us that. Uh, that’s true. Yeah.
COMMANDO #3: And the sanitation.
LORETTA: Oh, yeah, the sanitation, Reg. Remember what the city used to be like?
REG: Yeah. All right. I’ll grant you the aqueduct and the sanitation are two things that the Romans have done.
MATTHIAS: And the roads.
REG: Well, yeah. Obviously the roads. I mean, the roads go without saying, don’t they? But apart from the sanitation, the aqueduct, and the roads—
COMMANDO: Irrigation.
XERXES: Medicine.
COMMANDOS: Huh? Heh? Huh...
COMMANDO #2: Education.
COMMANDOS: Ohh...
REG: Yeah, yeah. All right. Fair enough.
COMMANDO #1: And the wine.
COMMANDOS: Oh, yes. Yeah...
FRANCIS: Yeah. Yeah, that’s something we’d really miss, Reg, if the Romans left. Huh.
COMMANDO: Public baths.
LORETTA: And it’s safe to walk in the streets at night now, Reg.
FRANCIS: Yeah, they certainly know how to keep order. Let’s face it. They’re the only ones who could in a place like this.
COMMANDOS: Hehh, heh. Heh heh heh heh heh heh heh.
REG: All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a fresh water system, and public health, what have the Romans ever done for us?
XERXES: Brought peace.
REG: Oh. Peace? Shut up!