The Bill of Rights is a much more fortuitous addition to the Constitution than many people imagine. The tired delegates at Philadelphia were unable to make the final effort to frame a bill of rights, and their failure nearly caused the collapse of ratification. When the First Congress met, James Madison took responsibility for making the new government live up to the implied pledge made during ratification to provide a partial list, drawn from the historic rights on English subjects. Not all Madison's proposed amendments were adopted however. The work of adumbrating the full scope of liberty under the Constitution goes on.
Speech: The Bill of Rights, 82 Ore. L. Rev. 517 (2003)