"49 of the states adopted English common law. Louisiana's Constitution is based on codified, or Roman law (sometimes erroneously called French law.)"
Why do you say it was erroneously called French law? It was French, as well as Spanish, which I believe were derived from Roman Law.
Because I dislike the French...
Sorry, joking. For the same reason that we call 1, 2, 3 etc. Arabic numbers and not English numbers. We got them from the English, but the English got them from the Arabs.