According to a story in the Washington Post, Dillon told his family that he etched his name, the date of the attack and a message on the inside of the timepiece. Years later, in 1906 - forty years after he inscribed the message - Dillon told a NY Times reporter specifically what the message was:
"The first gun is fired. Slavery is dead. Thank God we have a President who at least will try."
The watch was donated by the Lincoln family to the Smithsonian, where it is occasionally put on exhibit but is generally considered to be a "minor artifact."
The family of the watchmaker recently uncovered evidence that the family legend may indeed be fact; the Smithsonian decided to find out for sure. Yesterday, the watch was opened...and a message from the past was revealed:
"Jonathan Dillon April 13-1861. Fort Sumpter [sic] was attacked by the rebels on the above date thank God we have a government."
So Jonathon Dillon was both right and wrong when he told people about the message he'd left in Lincoln's watch. The message was real - but Dillon's memory had changed the details. In memory, his details were more vivid, his predictions of the future quite firm - and accurate. In his memory, he believed his message made note of his faith in Lincoln and that it included his prediction of the end of slavery.
The actual message made note only of the moment and indicated Dillon's appreciation of the much broader "government" - instead of Lincoln himself.
Memory is elusive. It can paint such a vivid picture - but memory also embellishes, adds facts, details, names and faces that may not necessarily have been included in the moment we remember. Dillon remembered the message, but the details he remembered had been strengthened by the facts that followed.