I may have missed this, but here is a reference to "Hanging Johnny", or more specifically, "Hangman Johnny". Actually it is two references to the same material. The earliest is from 1867 in an article entitled "Negro Spirituals", from THE ATLANTIC MONTHLY. The second is to a book entitled ARMY LIFE IN A BLACK REGIMENT, published in 1882, but referencing the year 1862. Both are by Thomas Wentworth Higginson. The song was being sung by a squad of men coming in from picket duty. Apparently these were freed slaves serving in the Union Army in South Carolina. The verses are:

    "O, dey call me Hangman Johnny!
          O, ho! O, ho!
      But I never hang nobody,
          O, hang, boys, hang!

    O, dey all me Hangman Johnny!
          O, ho! O, ho!
    But we'll all hang togedder,
          O, hang, boys, hang!"

http://books.google.com/books?id=250GAQAAIAAJ&pg=PA693&dq=Hangman+Johnny&cd=1#v=onepage&q=Hangman%20Johnny&f=false

And

http://books.google.com/books?id=ITcOAAAAIAAJ&pg=PA220&dq=Hangman+Johnny&cd=2#v=onepage&q=Hangman%20Johnny&f=false