mr. evelyn, what role to the politicians play in your book on this? >> politicians over the years that have made decisions that affect the city and putting rehabilitating the mall of washington. .. >> for example, the site where the lincoln conspirators were hung, that famous painting, that famous photograph is now a tennis court at fort mcnear. the place which garfield was shot on his way back to his williams college reunion was right in front of the imk building on the mall. there's a little tiny marker about as big as a frisbee that says this is where a president was shot. part of the thing is discovering this layered history of the city and going back to amazing things in the civil war. fort stevens, a part of washington, where abraham lincoln, there's a battle in washington. the confederate troops are approaching the city. abraham lincoln stands up, and they shoot at him. and somebody says, mr. president, you fool, they pull him down. one of the problems with the battle at fort stevens was the soldiers had to keep the citizens, sight seers back f