The title comes from the mystery novel 'And Then There Were None' by Agatha Christie which was also published under the title "The Ten Little Indians" in 1939.
Ben Pringle tells Matt that the gunfighters killed his grandson, Thad Ewing. This name is the first name of the newly introduced character Thad Greenwood and the last name of the actor who played him, Roger Ewing.
The title comes from the American folk song, a counting rhyme that was set to music and published in 1868 by Septimus Winner, a music publisher of Philadelphia.