The Times-Picayune is part of the fabric of New Orleans. The newspaper has been around in one form or another for 175 years, and has written much of the city's history. It covered the civil war, the racial integration of Louisiana State University in the 1950s and the BP oil spill in the Gulf in 2010. And there was Hurricane Katrina.

During the days after parts of this city were submerged, the Times-Picayune became world famous. Print publication was halted for a few days, but a small number of journalists and support staff ignored the looming storm, stayed at their desks and covered the disaster and its impact. The newspaper's website received millions of hits and its staff picked up two Pulitzer prizes for its reporting, the most prestigious award in US journalism.

The Picayune was formed in 1837, its name taken from a Spanish coin, which was also the cost of the newspaper. It merged with the Times Democrat in 1914 to form the paper we know today. At one point it employed more than 700 people and had a Sunday circulation of 184,000.

Newspaper readership in the US has been in decline since the 1960s but the scale of disappearing readers has increased dramatically in the internet age. Two big city papers, the Denver Rocky Mountain News and the splendidly named Seattle Post-Intelligencer have disappeared from newspaper stands in recent years (although the Seattle P-I still publishes online). Many smaller newspapers have also shut down.

The Newhouse family – which owns the Picayune – acknowledges that the newspaper is profitable, but a look through the pages some days reveals very few adverts. That's despite having one of the biggest readership rates in the country and a circulation of around 130,000. And so it's going to scale back – printing just three days a week and moving a lot of the journalism online. That means New Orleans will be the biggest city in the United States without a daily newspaper.

Paul Greenberg worked for the newspaper and still contributes a monthly column. He also teaches digital journalism and believes that in order to find a younger audience the Picayune has to switch its resources online. But he said that the online product has to be good.

"It needs to pour good money into hiring a determined, highly trained investigative reporting team that can produce in-depth stories of newspaper quality," he said.

New Orleans has a history of elected officials facing corruption allegations, some uncovered by the local newspaper. Jack Davis who worked at the Picayune, then ran a number of newspapers believes that a local newspaper acts as a watchdog.

"It has a very important function to act for the public," said Davis.

At a rally in the car park of a bowling alley on a hot, sticky afternoon, those who love the Times-Picayune have come to fight for its survival. Many wear T-shirts printed in the aftermath of Katrina, bearing the legend "We publish come hell and high water." One man tells me, "The owners know the Picayune makes money. The'’re only concerned about the bottom line. Why not about the common good?"

Anne Milling is on the Times-Picayune advisory board and one of those who organised the rally. She insisted the comeback from the Hurricane is not yet complete.

"The Times-Picayune has been our partner in our recovery since Katrina and they have provided the platform for civic dialogue, and community discussion and you’ve got to have that to move the community forward," she said.

The 200 or so that turned up found support from 50 community and business leaders who issued an open letter to the paper’s owners, urging them to reconsider the downsizing of the paper, or to sell to someone who would print a daily edition.

In a city that has lost so much in recent years, this is a loss many are ready to fight.

Follow Alan Fisher on Twitter: @AlanFisher