The writers of the US Bill of Rights and state constitutions relied on ispiration from concepts in in the Magna Carta. Those concepts are "that a government should be constitutional, that the law of the land should apply to everyone, and that certain rights and liberties were so fundamental that their violation was an abuse of governmental authority." [Cornell Law School, Legal Institute Information].

I guess here in the States, we've understood that the Magna Carta was the UK's constitution.