the document that was added to the constitution to gain the support of anti-federalists was called what

The Bill of Rights of the United States is the collective name given to the first ten amendments of the Constitution of the United States approved on December 15, 1791.

It was an answer to calm the fears of antifederalist groups, some of them influential opponents of the Constitution, and prominent members of the Philadelphia Convention, who argued that it failed to defend the basic principles of human freedom. These amendments guarantee a series of personal freedoms, limit the power of the government in judicial processes and others; and some faculties are reserved for the states and the people.