Bouncing down an empty country road, past browning cotton fields lined with signs advertising church services and cheap guns, historian John A. Lupton hunches over a minivan's steering wheel and ignores his aching back.

He has been traveling for six days -- covering five states and more than 1,400 miles -- in a mentally exhilarating and physically exhausting pursuit of anything handwritten by Abraham Lincoln, as well as documents addressed to him: a frayed envelope the president addressed to a Confederate sympathizer; a dirty sheet of paper filled with the grumblings of a cotton farmer; a faded journal entry with notes about property rights that Lincoln scrawled in the margins.

It's been a good trip so far. Lupton and his colleague Erika Nunamaker have tracked down 33 documents.

Over the last seven years, more than 11,000 pieces of paper with Lincoln's elegant script -- and nearly 28,000 documents addressed to him -- have been found. After the pair scan the papers onto their laptops, they return the originals to their owners, and move on to find the next yellowing scrap.

Lupton thinks there are tens of thousands of papers left to discover. Maybe more.

Curled up in the passenger seat, Nunamaker studies a paperback atlas to trace their journey. She rubs her queasy stomach and tries to ignore a bout of carsickness from days of driving along winding back roads.

"Gosh, I hope our luck holds," Nunamaker says. "We haven't seen a single forgery yet. Not like Florida."

Lincoln may be our most studied president, and is reportedly the subject of more books than any American. But that doesn't stop this road-weary pair and 10 other scholars from the Illinois-based Papers of Abraham Lincoln from fanning out on road trips four times a year.

It's part of an experiment in historical studies: to unify the great moments of a great man's life with the most mundane times captured on thousands of pieces of paper.

Lupton, 41, has spent more than two decades studying Lincoln's handwriting, figuring out when the man was thoughtful (by the neat, careful pen strokes) or tired (by the script's jagged lines). Nunamaker, who carries a worn picture of the 16th president in her wallet, has long been entranced by his private life.

"It's my dream," says Nunamaker, 28. "How many people can say they transcribe his words every day?"

In her eyes, and those of her colleagues, even the tiniest messages can be telling. The team has located hundreds of hastily signed military commissions. By tracing their origins, the scholars determined that Lincoln used such busy work to help stay awake at night while he cared for his ailing son.

They've digitally scanned Lincoln's terse responses on scores of petitions from political operatives seeking government office. Over time, they've deduced that Lincoln relied heavily on his Cabinet to fill government jobs.

They've transcribed dozens of letters from the families of jailed Confederates and Unionists, pleading for leniency. Lincoln's quirky and approving responses -- telling men they could be free after swearing an oath to support the United States -- were often written on the back of those letters.

"How can you really know a man unless you look at the sum of his work?" Lupton says. "And I do mean the entire sum."

Lincoln worked as a lawyer for nearly 25 years, generating reams of court filings and business correspondence. There were so many Lincoln documents floating around that in the days after his assassination in 1865, people raided courthouses and government offices to clip off his signature. For some, it was a treasured memento; for others, a way to cash in on his death.

The papers project began in the 1980s, when three scholars funded by the Illinois Historic Preservation Agency in Springfield started to hunt for every legal document and court case that Lincoln handled.

Lupton, considered one of the country's leading experts on Lincoln's signature, joined the team in 1991 as a graduate student intern. Poring over dusty legal ledgers, Lupton realized he had a talent for piecing together clues. While reading through pre-Civil War letters, Lupton and the team found mentions of Lincoln getting paid in a case involving bankers accused of bilking shareholders. Court documents elsewhere noted that the case had been moved to southern Illinois.

It was enough for Lupton and two other researchers to camp in the Macoupin County records office and flip through century-old judgments and water-stained contracts, page by page.