For a man who once had a pretty big presence in Washington, Crosby Stuart Noyessure had a pretty anemic presence on Wikipedia. At least, he did on Saturday morning, when the 19th-century publisher of the Evening Star newspaper’s listing on the crowdsourced, online encyclopedia was a mere two sentences long.

But by Saturday afternoon, Noyes had been supersized, or at least given a Wikipedia treatment a little more in keeping with his importance: seven paragraphs and five footnotes.

This was all thanks to Andrew Kuchling, who was one of about two dozen local history buffs who spent Saturday at the Historical Society of Washington engaged in a Wikipedia “Edit-a-Thon.” Their mission: Create, improve, correct and footnote Wikipedia entries related to our fair city.

Sure, these Wikipedians could work solo, in the privacy of their homes, but there’s something more communal about doing it together.

Of course, the Wikipedia Edit-a-Thon was a lot more sedate than other activities ending in “thon”: marathon, telethon, Toyotathon. . . . Picture studious people bent over their laptops at the polished wood tables of the society’s Kiplinger Research Library. Some had pulled reference materials from the library’s collection, others were looking for material online. Librarians and Wiki experts were available to help.

The first issue was what to tackle. The library had provided a list of possible starting points, a few people, places and things that many D.C. residents no doubt know about but that were absent on Wikipedia or inexpertly presented: Petworth, quadrants, Chuck Brown, Howard Theatre, School Without Walls, Walter Reed Army Medical Center, Sycamore Island, Snows Court. . . .

Crosby Stuart Noyes wasn’t on the list, but Andrew, who lives in Bowie and works as a software developer for a cable company, thought the guy could use some help.

“I think running the Evening Star all those years is fairly significant,” Andrew said. He’d fleshed out Noyes’s life using a 1932 book on notable D.C. figures from the society’s collection and added links to a newspaper article the journalist had written in his 20s.

After fixing the spelling of the middle name of one of Noyes’s son — it wasWilliams, not William — Andrew decided to beef up the two sons’ entries.

“It’s a way of exercising my writing skills, but I don’t need to work on it for days and days,” Andrew said. “Four hours is plenty.”

Rita Moore and Nicole Beyer sat across from one another one table over. Rita, an insurance agent by day, had the vertical file from the Petworth Citizens Association to one side and was contemplating tweaking the Petworthentry to indicate that the borders of that neighborhood have been somewhat flexible.

Nicole, a senior at George Washington University, was fleshing out the entry forConcordia German Evangelical Church and Rectory in Foggy Bottom, adding information on the value of the church’s property and how big the congregation was.

“I’m a big fan of Census data,” she said.

Adam Lewis, the historical society’s director of development and the person who in 2008 rescued Wikipedia’s main Washington, D.C., entry from mediocrity, described the perfect entry: verifiable, with proper citations and a neutral tone. And it can’t contain original research.

Said Adam, “You’d be surprised how many people say, ‘Well I live down the block, and I know X.’ ”

Just living down the block and knowing X doesn’t cut it on Wikipedia, which is why so many articles are flagged as needing work.

But what a vast and potentially dispiriting endeavor. At last count, there were 4,193,775 English-language entries on Wikipedia. All anyone can hope to do is nibble away at the errors contained therein and add tiny drops of information to the vast sea of knowledge.

“I think every little bit helps,” saidChloe Raub, a Catholic University library sciences student who was working on the listing for William R. Perl, an Austrian-born lawyer and head of the Jewish Defense League’s Washington office. “I think that what Wikipedia depends on is a whole lot of people taking a little time to make it better.”

At his computer, Adam scrolled through some other D.C.-related entries, clicking on Pierre Charles L’Enfant. The entry looked pretty good. Then Adam noticed something. “His entire early life is not cited,” he said disapprovingly.

Get cracking, Washington Wikipedians!

For previous columns, visitwashingtonpost.com/johnkelly.