The historical legal document that guaranteed freedom of speech and the abolishment of perceived tyrannies is the U.S. Bill of Rights, specifically the First Amendment. Ratified in 1791, the Bill of Rights comprises the first ten amendments to the United States Constitution, establishing fundamental rights and liberties. The First Amendment protects several freedoms, including speech, religion, press, assembly, and petition. This landmark document laid the foundation for American democracy, ensuring that individuals could express their ideas and dissent without fear of government repression, thereby promoting a culture of open dialogue and political discourse.