I found an usher’s diary at the Roosevelt Library that recorded what Franklin and Eleanor did every day. “Awakened at 6:30; had breakfast with Henry Stimson; had lunch with Joe Lash,” or whatever. I could then go to the diaries of the people they had lunch or breakfast with to record what they said at breakfast or lunch. Eleanor wrote 25 letters a day to her friends. I got every single one of those letters and figured out what her mood was like on that day. Made a huge chronology, before I even started the book, of 1940 to ’45, the years that I was covering, so that I could recreate every day, in a certain sense, in their lives.