Muddy
The Muddy Townsperson is seen throughout the play, and it is not until the final speech that we learn she is a metaphor for the stain of Mary's killing still dirtying the people of Erwin.
Hungry
The Hungry Townsperson is a metaphor for the need for the people of Erwin to remember their history, and on a larger scale it is a call for America to remember. The point being that when we remember we are able to be better, to to perpetrate the same acts as we have grown to know what is right. Hungry reminds us that we have a short memory and that must change.
Marshal
The Marshal is a metaphor for the corruption of the American Dream. In his final speech, he declares that Mary's killing proves that America can do anything, that dreams can come true.
Mary
The story of Mary's killing is true. With the passage of time Mary's story becomes a metaphor for how man punishes nature for not bending to its will, even though man's will has little to do with unity but rather profits. Mary's story represents how we as people seek to blame someone or something for why things happen, but we are unwilling to look at ourselves as being at the core of the issue.
Engineer
The Engineer is a metaphor for the progress of America, that above all else Time must be kept. His engine moving on the tracks from town to town on a schedule that cannot be broken, not even by tragedy represents America's never ending hunger for more.
