John Peter Zenger (1697–1746) was a New York City printer who was accused of seditious libel in 1735. His case changed the definition of libel in American courtrooms and laid the foundation for freedom of the press.

The German-born Zenger immigrated to the American colonies in 1710, when he was 13 years old. He found a job as a printer’s apprentice, working on the colony’s official newspaper, the New York Gazette. Fifteen years later he began his own operation, which was mostly concerned with printing religious pamphlets. In 1733 New York received a new colonial governor from England: William Cosby quickly earned the contempt of the colonists, both rich and poor. Prosperous businessmen who opposed Cosby and his grievous tactics approached Zenger, offering to back a newspaper that he would both edit and publish. Zenger agreed and on November 5, 1733, the first issue of the Weekly Journal was released. It included scathing criticisms of the royal governor, raising Cosby’s ire. After burning several issues of the papers, Cosby had Zenger arrested in November 1734. The editor-publisher continued to operate the journal from inside his jail cell, dictating editorials to his wife through the door.

Zenger’s case went to trial in August 1735. Prominent Philadelphia attorney Andrew Hamilton (1676–1741), considered the best lawyer in the colonies, came to Zenger’s defense. Hamilton admitted his client was guilty of publishing the papers, but, he argued, that in order for libel to be proved, Zenger’s statements had to be both false and malicious. The prosecution contested the definition of libel, asserting that libelous statements are any words that are “scandalous, seditious, and tend to disquiet the people.” The court agreed with the prosecution, and Hamilton was therefore unable to bring forth any evidence to support the truth of the material Zenger printed in the Weekly Journal. The defense argument was not heard until the closing statement was made by Hamilton; his summation stands as one of the most famous in legal history. He accused the court of suppressing evidence, urging the jury to consider the court’s actions “as the strongest evidence,” and went on to declare that liberty is the people’s “only bulwark against lawless power. Men who injure and oppress the people under their administration provoke them to cry out and complain.” The brilliant attorney closed by urging the gentlemen of the jury to take up the cause of liberty, telling them that by so doing, they will have “baffled the attempt of tyranny.” The seven jury members were convinced by Hamilton’s impassioned speech and found Zenger not guilty.

Discharged from prison the next day, Zenger returned to his printing business, publishing the transcripts of his own trial. While colonial officials were reluctant to accept the case’s ruling on the definition of libel, the case became famous throughout the American colonies. And once the colonists had thrown off England’s royal rule and established a new republic, the nation’s founding fathers codified the Zenger trial’s ruling in the Bill of Rights: The First Amendment to the U.S. Constitution guarantees freedom of press.