>> guest: volokhs slow you down. you wait in line and there are often many ships in than going through the locks takes a little bit of time but also the ship goes slowly through the vast a tune lake that dominates the canal. it's a beautiful journey. it was fun to do it on a ship with lots of people pointing out gold hill or other landmarks that by the end of the day you are tired and you have seen so much, you are ready for some dinner. >> host: professor green a lot of the focus when we talk about panama canal is on president theodore roosevelt and in your book "the canal builders" you have a picture of president roosevelt but he's not the focus of your book. >> guest: that's right. he dominates our memory of the canal and for good reason. he more than any other single person played a huge role in committing the united states to building the canal but my book doesn't focus on him because i'm interested in looking at the working men and women who built the canal. part of what inspired the book was thinking that the