True , the US is the only country to adopt a Bill of Rights.
Explanation
The bill of rights is the 10 amendments that in accordance with the Constitution is made to improve the welfare of American citizens.
It provides the basic rights of all citizens of America.
It envisions that people are the ultimate power in this country and not the Federal Government.
Its effect was due to the influence of George Mason's Virginia Declaration of rights.
It was anti-federalists that took forward the notion that such a bill is mandatory for freedom.