A J.D. is considered a terminal degree (there is no further degree beyond a J.D.; the S.J.D. is considered a different track), so technically you do have a doctorate.
But ethical rules are questionable as to whether you can call yourself a "doctor," because it's potentially misleading. So US lawyers are in the strange position of having doctorates, but being unable to say so.
I think that is the conventional use of the term "esquire" in the United States, but I can't recall the last time when I saw a lawyer use that title. Most lawyers like best the title "attorney at law," which is the title for the regulated occupation they enjoy once they have passed a state bar examination.
But ethical rules are questionable as to whether you can call yourself a "doctor," because it's potentially misleading. So US lawyers are in the strange position of having doctorates, but being unable to say so.
Here's some more info: http://abajournal.com/magazine/lawyers_are_doctors_too/