In 1812, a violent mob broke into a Baltimore newspaper office and attacked its owner Alexander Contee Hanson, whose articles opposing the War of 1812 angered them. In an example of lack of protection of press freedom, government officials refused to defend the newspaper owner and his defenders, even in jail, where another attack occurred, killing one and disfiguring another.

Anthony Lewis was a Pulitzer Prize-winning journalist who covered the
Supreme Court for the New York Times and authored several First Amendment
books.

Edward R. Murrow was one of the creators of American broadcast journalism.
Murrow inspired other journalists to defend and perpetuate the First
Amendment rights.

Fred W. Friendly, an early innovator of broadcast journalism, was also
known for his seminars on the media and public issues and for his writings
on the First Amendment.

Ida B. Wells (1862-1931) was an African American woman who was born into
slavery in Mississippi and eventually became the co-owner and editor of the
Memphis Free Speech.

James G. Birney (1792-1857) founded the abolitionist newspaper, the Philanthropist. In 1836, a mob destroyed his press and went on to riot several nights, attacking Black homes in the city. A group, calling themselves “the friends of Order, of Law, and the Constitution” that included future Supreme Court Justice Salmon Chase  criticized such actions. They observed

John Seigenthaler was the longtime editor of The Tennessean in Nashville,
known for championing civil rights. He founded the First Amendment Center
at Vanderbilt University in 1991 and became a national leader in promoting
First Amendment values.

Joseph Pulitzer came to the United States in 1864 as a restless Jewish immigrant from Hungary. He knew little English. Despite poor health and weak eyesight, he had contracted with a bounty hunter in Germany to be paid to fight for the North in the Civil War as a substitute for a draftee – something

Judith P. Miller, a Pulitzer Prize–winning investigative journalist, went
to jail rather than testify before a federal grand jury about a
confidential source.

Kenneth A. Paulson has led several national programs to increase
understanding of the First Amendment and its role in society. He is former
editor in chief of USA Today.

Nat Hentoff, a civil libertarian, jazz critic, and self-described
troublemaker, spent much of his career defending the First Amendment
against a variety of perceived threats.

In the 1847 Ritchie Affair, the U.S. Senate revoked floor privileges its official printer Thomas Ritchie who also was editor of a partisan newspaper after he published an article suggesting a senator was on the side of Mexico in the Mexican-American War. Although the Ritchie affair was short-lived, it raised significant issues about freedom of the press, including free speech during wartime and congressional pressure on political reporting.

Author and muckraker Upton Sinclair is better known for his novels. But he was once arrested and jailed in Los Angeles in 1923 after trying to read the First Amendment in a public place in protest of mass arrests of striking dockworkers.