Tom Albin uses his lunch break to time-travel.

On the desktop computer at his home office in Minneapolis, the industrial engineer studies the spiky penmanship of another century, squinting to decipher top-secret telegrams from Abraham Lincoln's War Department.

"It sucks you in," said Albin, a lifelong Civil War enthusiast and a descendant of a Union private who rode in an Iowa cavalry regiment.

As a "citizen archivist," he's one of thousands of amateur historians and codebreakers from around the country who donate their spare time to help unlock the secrets of the past.

Volunteers are logging on — at ­decodingthecivilwar.org — to transcribe thousands of long-lost wartime missives using a crowdsourcing platform developed and managed, in part, by the University of Minnesota.

Civil War historians had long speculated that there were books that contained the scripted, dash-and-dot messages sent to and from the battlefields.

Before the Civil War, couriers were relied on to carry written battlefield instructions or updates. But by the mid-1860s, the breakthrough technology of the telegraph allowed for real-time exchanges between Union officers in the field and Washington-based Cabinet members — and even the Great Emancipator himself.

"There are mentions of Lincoln in the telegraph office holding the ledgers. What happened to them was unknown," said Mario M. Einaudi, the digital project librarian for the Decoding the Civil War project. "It was assumed they'd been destroyed."

But in 2009, two wooden trunks holding 35 ledger and code books turned up and were sold at auction. The archive had been apparently been taken by Thomas T. Eckert, head of the Civil War telegraph program, when he left government service.

"Eckert's descendants found the ledgers, but didn't know what they had. The dealer who sold them to us in 2012 understood their importance," explained Einaudi, who is on staff at the California-based Huntington Library, which bought the Eckert archive to complement its extensive Lincoln collection. "These daily messages represent a granular look at the grinding wheels of history."

With almost 16,000 messages, the telegram cache is so dense, so massive, that Einaudi predicted that it would take a full-time staff as long as a decade to painstakingly decipher the messages one by one.

That's where the crowdsourcing comes in.

Code name: Zebra

Starting this past June, volunteers from across the country have been able to register on the Decoding the Civil War website, take a quick tutorial and begin scrutinizing the scanned copies of the original telegrams. A two-year grant from the National Historical Publications and Records Commission is backing the project.

Already, volunteers have decoded a telegram from Gen. William Tecumseh Sherman mourning the death of his 9-year-old son in Vicksburg, while another questions how to handle Union deserters. There's a whole thread following the Union's surrender at Harpers Ferry, W.Va.

"So far the ones I've transcribed were pretty straightforward," said Albin, "but one of them used the name 'Zebra' instead of an officer's name."

In his years studying the war, Albin developed a particular fascination with the 1862 Peninsula Campaign, a large-scale Union effort to capture the city of Richmond, Va. It was ultimately thwarted by the Confederate Army under Robert E. Lee.

Albin was thrilled when several telegrams he transcribed appeared to be about Union maneuvers in northern Virginia.

"It was so interesting to see the instantaneous transmission of information between the battlefield and headquarters in Washington," he said.

Because the handwriting of the 1860s is filled with flourishes and quirks that have long passed from style, volunteers often debate the meaning of the scribblings on the website's talk boards.

"We have people online 24 hours a day," Einaudi said. "When you increase the eyeballs, you increase consensus, the wisdom of the crowd."

The project's user-friendly portal was developed by Zooniverse, a crowdsourcing platform associated with the University of Minnesota and several other academic and research institutions.

"The great part is that so many people can have firsthand experience with these primary documents," said Andrea Simenstad, a Zooniverse developer at the U. "It's a personal way to interact with this time in history."

Eyes, not algorithms

Although advances in technology allow for easy access for volunteers, nothing in the digital era can supplant the human eye. Only engaged volunteers can provide the close scrutiny required to decode the archaic script.

"We can't build an algorithm that can do this kind of work," said Lucy Fortson, U Zooniverse director. "Humans have developed this beautiful visual cortex that allows them to see complex patterns, distinguish visual information and type what they see.

"Machines can do data analysis, but they aren't any good at reading handwriting."

She said she is heartened by the enthusiasm the volunteers show as they dig into these wartime puzzles.

"We know there is much cognitive capacity out there," she said.

"A certain type of person is predisposed to volunteering on a site like this. We see a hankering to be involved with something meaningful, and research translates as meaningful. With crowdsourcing, they have a bit of ownership in what we might find."

Although the project has been underway for several months, it's not yet clear what secrets might be hidden in the yellowed pages of the ledgers.

"This may not revolutionize the study of the Civil War," Einaudi admitted, "but I like to say that it will likely shine light in corners that are dimly lit."

For Albin — who keeps several shelves of Civil War history books, is active in the Twin Cities Civil War Roundtable and has inherited the musket carried by his great-grandfather — the volunteer work is a unique chance to be immersed in an era that has long fascinated him.

"I think this can enrich the context of what we know," he said. "With 16,000 telegrams, some original insights are bound to come out.

"And who knows which one of us will find it?"

Kevyn Burger is a Minneapolis-based freelance writer and broadcaster.