More than 300 news outlets have launched a campaign to counter President Donald Trump's attacks and promote a free press.
The Boston Globe made the call last week for a nationwide denouncement of the president's "dirty war" against the media, using the hashtag #EnemyOfNone.
Mr Trump has derided media reports as "fake news" and attacked journalists as "enemies of the people".
UN experts have said this raises the risk of violence against journalists.
UN experts condemn Trump media attacks
Why Trump attacks the media
The Boston Globe had pledged to write an editorial "on the dangers of the administration's assault on the press" on 16 August, and asked others to do the same.
The initial positive response from 100 news organisations has grown closer to 350 with major US national newspapers and smaller local outlets answering the call, along with international publications like the UK newspaper The Guardian.
What have the papers said?
Starting with the Boston Globe itself, the editorial there, headlined Journalists Are Not The Enemy, argued that a free press had been a core American principle for more than 200 years.
The New York Times chose the headline A Free Press Needs You, calling Mr Trump's attacks "dangerous to the lifeblood of democracy". It published excerpts from dozens more publications beneath.
The New York Post - a pro-Trump tabloid - answered the Globe's call by saying "Who are we to disagree?" adding: "It may be frustrating to argue that just because we print inconvenient truths doesn't mean that we're fake news, but being a journalist isn't a popularity contest. All we can do is to keep reporting." But it also said: "Will this make a difference? Not one whit".
The Philadelphia Inquirer said its city was the birthplace of US democracy, writing: "If the press is not free from reprisal, punishment or suspicion for unpopular views or information, neither is the country. Neither are its people".
Opinion writers at McClatchy put out an editorial for the 30 daily newspapers it runs, including the Miami Herald, saying they hardly ever spoke with one voice but were doing so now. It said "enemies of the people" was "what Nazis called Jews. It's how Joseph Stalin's critics were marked for execution".
Another paper to join the campaign was the Topeka Capital-Journal which said of Mr Trump's attack on the media: "It's sinister. It's destructive. And it must end now." The paper was one of the few to endorse Mr Trump in 2016.