The significance of the First Amendment in the U.S. Constitution lies in its protection of fundamental freedoms, including speech, religion, press, assembly, and petition. Ratified in 1791 as part of the Bill of Rights, it ensures that individuals can express their opinions freely and criticize the government without fear of persecution. This amendment forms the cornerstone of American democracy, fostering a diverse public discourse essential for a functioning society. It empowers citizens to advocate for change, challenge injustices, and promotes the marketplace of ideas. Its enduring impact can be seen in numerous landmark Supreme Court cases that define and uphold these rights.