The significance of the Bill of Rights in American history lies in its role as the first ten amendments to the U.S. Constitution, safeguarding individual liberties and limiting government power. Ratified in 1791, the Bill of Rights addressed concerns raised by Anti-Federalists who feared an overly powerful federal government. It guarantees fundamental rights such as freedom of speech, religion, and the right to bear arms, promoting democratic principles and civil liberties. The Bill of Rights has since served as a foundation for legal and political discourse, influencing numerous Supreme Court decisions and shaping American identity and values.