Who is this person?

[RJNorton]

To show the degree to which Abraham Lincoln's life has been explored, a person once wrote a 400+ page book on something that is missing. What am I talking about?

[AussieMick]

Lincoln's "Lost Speech" at the Bloomington Convention ?

[RJNorton]

Excellent, Michael. Although the text of Lincoln's Lost Speech is missing, Elwell Crissey was still able to write a 400+ page book on the topic. Crissey includes a lot of extra information such as many paragraphs of information on the people who attended the 1856 Bloomington Convention. Crissey's paternal grandfather was in the audience for Lincoln's speech.

Benjamin P. Thomas wrote, "The audience sat enthralled. Men listened as though transfixed. Reporters forgot to use the pencils in their hands, so that no complete and authentic record of what may have been his greatest speech has ever been found."

[AussieMick]

I recall reading that "Reporters forgot to use the pencils in their hands" somewhere. It's very evocative writing in just a few words.