According to the Preamble to the Bill of Rights, why was the Bill of Rights consid ered necessary ? Preamble Congress of the United States begun and held at the City of New York, on Wednesday the fourth of March, one thousand seven hundred and eighty-nine THE Conventions of a number of the States, having at the time of their adopting the Constitution, expressed a desire, in order to prevent misconstruction or abuse of its powers, that further declaratory and restrictive clauses should be added: And as extending the ground of public confidence in the Government, will best ensure the beneficent ends of its institution RESOLVED by the Senate and House of Representatives of the United States of America, in Congress assembled, two thirds of both Houses concurring, that the following Articles be proposed to the Legislatures of the several States, as amendments to the Constitution of the United States, all, or any of which Articles, when ratified by three fourths of the said Legislatures, to be valid to all intents and purposes, as part of the said Constitution; viz1 ARTICLES in addition to, and Amendment of the Constitution of the United States of America, proposed by Congress, and ratified by the Legislatures of the several States, pursuant to the fifth Article of the original Constitution
A the Bill of Rights was needed to ensure the power of Congress to pass and enforce laws 

B the government of right, was needed to protect the people against abuse power by the government.

C the Bill of Rights was needed to prevent any state from ignore federal authority.