On April 12, 1861, President Lincoln was having his watch repaired. This day also marked the start of the Civil War. When the watchmaker Jonathan Dillon heard of this momentous event, he inscribed a message into Lincoln's pocket watch as he repaired it. The story of the inscription was passed down over the years in the Dillon family but was never confirmed until the Smithsonian's National Museum of America History decided to open Lincoln's pocket watch. Watch the video above and see how history was discovered nearly 150 years later and read the blog post at the great O Say Can You See?