Jim, for me it was a combination of Twenty Days and The Day Lincoln Was Shot. That was in the 1960's. The photos in Twenty Days made an indelible impression on me. Beginning in the 1970's I did a simulation of the 1865 conspiracy trial with my classes each year. It was my favorite unit, and a favorite among the students as well. I also like the fact that the story of the assassination does not need any embellishing; it is fascinating as is. To this day we are still far away from knowing the whole story.