On the 10th anniversary of the end of the Civil War, there were no special newspaper sections remembering its great battles or dwelling on its meaning. The leading media of the time remarked on the milestone but acknowledged it with restraint. The New York Times and the Chicago Tribune published just 12 stories each about the war during the entire month of its decennial, including one story in the Tribune announcing an Army reunion.

Likewise, as columnist George Will pointed out in his Sunday Op-Ed column, the 10th aniversary of Pearl Harbor drew a few modest newspaper mentions.

Contrast that with Sunday’s 10th anniversary of Sept. 11, 2001, a day that has been documented, dissected and debated unlike any other in human history.

On TV and radio, in print and online, over social media that didn’t exist 10 years earlier, the tributes, reflections and search for meaning have poured forth in a kind of collective media-fed group therapy. Where were you that day, many news organizations asked? What do you remember? On Sunday, it was impossible to forget. Eight networks carried live coverage of the official memorial ceremonies at the Pentagon, Ground Zero and Shanksville, Pa. The NFL waved field-size American flags during its marquee matchups, including the symbolic New York-Washington game between the Giants and Redskins.

Every outlet had an angle; a Web site called Food Republic surveyed chefs about their memories (“I would never forget the feeling of me cooking that night,” one said).

“I think this is what 24-hour news cycles result in,” said Gene Roberts, a former editor of the Philadelphia Inquirer and New York Times. “If you have a lot of time to fill, anniversaries are something [the media] can plan ahead on. . . . I guess I can think of some important milestones that got coverage, but not like this.” At the same time, he added, “this was one of the more traumatizing events in American history.”

Americans have always reflected on the anniversaries of significant and solemn days — Dec. 7, 1941; June 6, 1944; and Nov. 22, 1963, among them — but probably none has rated the buildup and attention of this anniversary.

Much of it, of course, is due to the unique and far-reaching nature of Sept. 11 itself. Its consequences and associations are insinuated into daily life, from the mundane act of taking one’s shoes off in an airport security line to the neo-tradition of singing “God Bless America” instead of “Take Me Out to the Ball Game” at ballparks.

Many anniversary stories assessed how that one day changed something: international relations, domestic politics, warfare, air travel, architecture, movies. Others asked American Muslims how the years since the attacks have affected them. A few stories (like this one) covered the coverage. More than a few (including in Sunday’s Post) concluded that “everything” had changed.

An overriding theme was “you.” USA Today produced brief videos of people answering the question, “How has 9/11 changed you?” (Regis Philbin said it made him feel “angry . . . sad”) and asked readers to contribute their own videos. More than 35,000 people submitted comments to the New York Times in answer to its question, “Where Were You on Sept. 11, 2001?”

The inescapability of it “must be very hard for the families who lost someone,” said John Farmer, dean of the Rutgers University Law School in Newark and a former senior counsel to the 9/11 Commission, the government’s official investigatory panel. “Obviously, the 10th is a significant anniversary, but to go through this every year must be a very hard process. No one wants the date to become like Memorial Day, where you have a Macy’s sale, but I’m sure they also don’t want to relive it as intensely as this.”

Farmer last week helped oversee the public release of recently declassified audio recordings of air-traffic controllers, military officials and pilots as they experienced the horror of the airline hijackings. Transcripts of the conversations have previously been released, but not the recordings themselves, making their disclosure one of the few new developments of the anniversary week.

The recordings have gotten more than 7 million hits on the Rutgers Law Review’s Web site since their release, Farmer said.

The tapes’ release suggests the full story of Sept. 11 is still far from fully told. Only about 20 percent of the vast archive of interviews, documents, recordings and other material collected by the 9/11 Commission has been declassified so far, Farmer said, suggesting that some details may not be disclosed for generations.

One important piece of the historical record that remains under seal, he said, is a recording of the so-called Air Threat Conference Call emanating from the White House on the morning of the crisis. The call involved Vice President Richard B. Cheney, Defense Secretary Donald H. Rumsfeld and a rotating series of officials who reported their reactions in real time. Only a few people outside of the members of the 9/11 Commission have ever heard the recording, he said.

For this anniversary, few journalists offered a “counter-narrative” to the prevailing Sept. 11-changed-everything paradigm, says W. Joseph Campell, a communications professor at American University. Campbell, the author of “Getting It Wrong: Ten of the Greatest Misreported Stories in American Journalism,” conducted a database search of post-Civil War newspaper reporting.

In fact, many facets of American life were unaffected by the event and its fallout, he said, and many of the purported changes immediately after haven’t held up over time. Since Sept. 11, for example, polls have found that Americans are less spiritual (as measured by religious-service attendance), less willing to display the flag, and less interested in keeping up with the news. Military enlistment, on the upsurge after Sept. 11, has fluctuated since then. “I don’t see the evidence of great change,” Campbell said.

Will Americans revisit and relive Sept. 11 with such passionate feelings and attendant media coverage on future anniversaries? Will 15 or 20 or 25 years out be the same as 10?

Given the human capacity to forget and for memory to fade, it’s possible to imagine that this was a high-water mark.

Pieces of the narrative — the heroism of first responders, the security lines, the wars waged in its aftermath — will remain vivid in the minds of this generation of Americans for decades, said Brian Monahan, a sociologist at Iowa State. But the fervor will ebb, he said. Already, says Monahan, the author of “The Shock of the News: Media Coverage and the Making of 9/11,” he has seen signs of “9/11 fatigue” in reaction to the media’s intensive coverage.

What’s more, new generations won’t be stirred by the same touchstones. Gene Roberts recalls teaching a journalism class at the University of Maryland in the early 1990s. In laying out his subject — a survey of press coverage of the civil rights movement of the 1950s and ’60s — he told his students that they would be discussing sit-ins and the Freedom Riders. Hands shot up.

“What are sit-ins?” “What are Freedom Riders?” Roberts recalls his students asking.

Roberts had lived through the civil rights era, which changed America as profoundly as Sept. 11 did. His students were too young to remember.