In the Unite States, the Bill of Rights is the name by which the first ten amendments to the United States Constitution are known. They were introduced by James Madison to the First United States Congress in 1791 as a series of constitutional amendments, and came into effect on December 15, 1791, when they had been ratified by three-fourths of the States. The Bill of Rights limits the powers of the Federal government of the United States, protecting the rights of all citizens, residents and visitors on United States territory.