John Wilkes Booth, the 26 year-old actor and later assassin of President Lincoln, was photographed many times over the course of his life. The numeration for his photographs is based on the 1979 book, John Wilkes Booth Himself by Richard and Kellie Gutman. Further information about these photographs can be found in their book.
This image was discovered after the publication of the Gutman’s book. See page 6 here: http://www.railsplitter.com/wordpress/PDF/Vol3No4.pdf