Every living soul can recall with certainty what they were doing when a national tragedy occurs—the day the Japanese bombed Pearl Harbor, the day in Dallas when John F. Kennedy was assassinated or the events of September 11.

Yet, no one alive today can recall the tragic day in 1861 when Confederate forces fired on Fort Sumter, beginning a terrible and tragic war that divided this nation and changed it forever. This week, a stunning find unveiled a personal record that touched the highest levels of government but remained hidden for nearly a century and a half.

On April 13, 1861, Irish immigrant and watchmaker Jonathan Dillon, working for the M.W. Galt and Co. jewelers in Washington, D.C., was repairing President Abraham Lincoln's pocket watch, when he heard of the attack. Forty-five years later, Dillon told the New York Times what he did that day.

"I was in the act of screwing on the dial when Mr. Galt announced the news. I unscrewed the dial, and with a sharp instrument wrote on the metal beneath: ‘The first gun is fired. Slavery is dead. Thank God we have a President who at least will try.'"

On Tuesday morning, at the National Museum of American History, some 40 reporters and Smithsonian staff witnessed master craftsman and jeweler George Thomas of the Towson Watch Company open Abraham Lincoln's watch to search for Dillon's secret message. Dillon's message was there, but not exactly as he later described it. News of the message inside Lincoln's pocket watch made every local broadcast and the front page of the New York Times. It was a rare moment when a museum, dedicated to the preservation of American history, could be said to be making history. And therein lies a tale.

The watchmaker and the President would never meet. And Lincoln would never know that he carried Dillon's secret message in his pocket.

Lincoln's watch is a fine gold timepiece that the 16th president purchased in the 1850s from a Springfield, Illinois jeweler. It has been in the safe custody of the Smithsonian Institution since 1958—a gift from Lincoln's great-grandson Lincoln Isham.

Harry Rubenstein, chief curator of the museum's bicentennial exhibition "Abraham Lincoln: An Extraordinary Life" (on view through 2011), has a fondness for the watch, which today would be the equivalent of a high-end Bulova or Tag Heuer.

"When you think about Lincoln especially at this point in his life," Rubenstein says, "his ill-fitting clothes and mussy hair; he doesn't seem to care about his appearance.

But in fact, he does care about how people perceive him. One of the status symbols of the 19th century is a gold watch. Lincoln is making a statement. He's carrying a very visible statement of his own success."

This story is full of ironies. And so we must pause here to reflect on one. It was February 12, Lincoln's 200th birthday, when the phone on Rubenstein's desk rang. The caller was Douglas Stiles, a 59-year-old attorney and genealogy expert, from Waukegan, Illinois. Stiles is also Dillon's great, great grandson.

The evidence was not overwhelming. All that Stiles had to offer was a bit of family lore and a newspaper article written 45 years after the fact. Could the stranger calling convince a museum curator to pull a national icon from display, to bring in an expert craftsman to disassemble the delicate, historical artifact, and to take a huge chance that nothing, in fact, could be there?

But, Rubenstein's interest was piqued and the decision was made.

"It's sort of amazing," Rubenstein said in an interview last week before the watch was opened, "when you think that two years before the Emancipation Proclamation, Abraham Lincoln is carrying this hopeful message in his pocket, and never knowing it."

A month after that initial call, in an elegant museum back room, photographers crowded around jeweler George Thomas who was seated at a makeshift craftsman's bench. As the hour approached, Rubenstein solemnly stepped forward. Lincoln's gold pocket watch was delivered to the bench.

Thomas went to work with tiny screwdrivers, tweezers and levers. Stopping occasionally to flex his fingers, he added tension to anticipation. "It will be awhile," he warned, obviously enjoying the drama. Stiles, accompanied by his wife Betsy and his brother Don from Bloomington, Minnesota, took a few deep breaths and readjusted himself in his chair. Finally Thomas, after unscrewing several tiny pins from the watch face, delicately lifted the plate and murmured, "The moment of truth."

Douglas Stiles is invited to read his ancestor's inscription:

"Jonathan Dillon April 13-1861 Fort Sumpter [sic] was attacked by the rebels on the above date J Dillon April 13-1861 Washington thank God we have a government Jonth Dillon."

The message was there. Yet there is no mention of slavery, nor did it say anywhere that Lincoln was the right man for the job.

Perhaps Dillon had grander intentions in mind as he hurriedly etched his note into the watch on that fateful day. In the march of time, what human doesn't add a flourish or two?

One thing is also clear. Dillon wasn't the only one with presidential pocket watch access. For there alongside the Dillon inscription is yet another—"LE Grofs Sept 1864 Wash DC." Who would that be?

And across one of the brass levers, the name "Jeff Davis" is scrawled. Lincoln's pocket watch got around.

Stiles was satisfied. "I feel more in touch with Lincoln," and then with a grin, he adds, "Hey, that's Lincoln's watch and my ancestor put graffiti on it."