Why did Americans insist on adding the Bill of Rights in the Constitution?

Two years after the constitution went into effect, ten amendments were added to the document. it was felt that the constitution did not list the rights that should protect all Americans. The constitution assumed that because the powers of the government were specific and limited, a statement of rights was not needed, but as the states began to ratify the constitution in 1787 and 1788, they insisted that a Bill of Right be added.