Best-selling author Simon Winchester discusses his new book, "The Men Who United the States." The unity of our nation is not just a political or social phenomenon. It is also physical, made possible throughout our history by roads, canals, railroads, telegraph lines – up to and including the Internet. The story of how Simon Winchester came to write the book is as fascinating as the book itself.

Also, Stewart talks to Matt Reeves, the Chief Archeologist at Montpelier, James Madison’s historic home in Orange, Virginia.