The Articles of Confederation provided a poor sort of national government. The “United States” received scant respect either from foreign or state governments. The men who authored the Constitution were determined to correct this fault. However, they knew that the great majority of Americans feared the power and ambition of any central government. Like the British monarchy, even the most “liberal” government might become tyrannical. For example, a government might seek to abolish slavery in the Southern states merely because a numerical majority found it abhorrent.
Consequently, James Madison designed a government based on the separation of powers. The executive, the legislature, and the judiciary would be co-equal branches of government. Each branch would work to hold in check the pretensions of any over-mighty individual branch.
Some delegates to the constitutional convention in Philadelphia worried that these provisions did not go far enough in insuring individual liberty. Elbridge Gerry and George Mason proposed addition of a bill of individual rights. This was rejected. Later, Richard Henry Lee proposed that a bill of individual rights be added to the Constitution. This, too, failed.
James Madison had argued against any bill of rights. He believed that such a bill would do no good against a “republican” government based on popular sovereignty. That is, the “people” would brook no opposition from a minority. Furthermore, a government might interpret a Bill of Rights as stating the maximum, rather than the minimum, liberties of the people. However, during the ratification process it became apparent that many ordinary citizens shared the reservations of Gerry, Mason, and Lee. Essentially, they believed that even the most “liberal” government might become tyrannical over time. Madison had argued that no bill of rights need be included because the division of powers and the conflict between interest groups would hold tyranny at bay. This argument failed to persuade many of his readers. The promise to add a Bill of Rights then became a bargaining chip in the effort to persuade state conventions to ratify the Constitution. Six states recommended that a Bill of Rights be adopted once the Constitution had come into effect. There were only 13 states then, so…
Madison abandoned his opposition to a Bill of Rights. He wrote his own. He offered these to Congress in June 1789. He proposed to splice-in Amendments One through Five within the Constitution itself in Article I, Section 9, between Clauses 3 and 4. Clause 3 bans Bills of Attainder. Clause 4 bans direct taxation except equally according to the census. In short, Madison intended that the Bill of Rights be individual rights.
Added instead as an appendix to the Constitution, they were adopted by Congress and ratified by the required number of states by December 1791. Critically, the Ninth Amendment stated that “The enumeration of certain rights shall not be construed to deny or disparage others retained by the people.” In this way, Madison responded to his fear that a tyrannical government might treat a Bill of Rights as a maximum statement of the rights of individual citizens.
Subsequently, the courts, including the Supreme Court, held that the “right of the people” referred to the rights of individuals. Freedom of religion is an individual right. Freedom of speech is an individual right. The freedom to petition for redress of grievances is an individual right. The right to be safe from unreasonable search and seizure of papers is an individual right. The right to not be compelled to testify against oneself in a court of law is an individual right. The right to trial by an impartial jury is an individual right. The right to not suffer cruel or unusual punishments is an individual right. God save the United States of America.
 Although that left the danger that two branches might, for their individual reasons, gang-up on the third branch.