Final answer:
The Sedition Act was believed by many to violate the First Amendment of the U.S. Bill of Rights, which protects freedom of speech and freedom of the press.
Step-by-step explanation:
Many Americans claimed that the Sedition Act violated the First Amendment of the Bill of Rights. The Sedition Act of 1918 forbade any 'disloyal, profane, scurrilous, and abusive' language towards the U.S government and its symbols, which many viewed as a direct infringement on the constitutional promise for freedom of speech and freedom of the press.
Despite the Supreme Court upholding the act, opposition from figures like Eugene V. Debs and organizations such as the National Civil Liberties Bureau soon emerged. Over time, most of these laws have been repealed, but the debate over civil liberties, especially during wartime, continues to be relevant.