Background information from website:
In the period following the ratification of the Constitution, the government of the United States was under Federalist control, first with George Washington and then under the presidency of John Adams. John Adams (1797-1801) and the Federalists, fearful of internal dissent while embroiled in international conflict with France, sought to reduce effective opposition through the enactment of a series of laws by Congress known as the Alien and Sedition Acts.
Under the Sedition of Act of 1798, it was illegal to criticize the government of the United States under penalty of fines and/or imprisonment.
Thomas Cooper, a lawyer and newspaper editor in Sunbury, Pennsylvania, was indicted, prosecuted, and convicted of violating the Sedition Act after he published a broadside that was sharply critical of President Adams. In part, Cooper was reacting to an article about himself that had appeared in the Reading (Pennsylvania) Advertiser. The case went to court in Philadelphia in April 1800.
Clearly a tool for political repression, the Sedition Act was later repealed after Thomas Jefferson won the presidency. Future iterations of similar legislation that restrained free speech would be struck down through the process of judicial review. Before this, however, speaking out in opposition to governmental policies could have serious legal repercussions as seen in the case of United States v. Thomas Cooper.