There are not a lot of symbols in Dreiser's novel; it is a work of naturalism, "the literary movement that believed an individual's life is determined by environment, heredity, and chance; survival of the fittest and natural selection govern an indifferent universe." But two symbols come up now and again: the genie and the bird. Both represent Clyde's desire to escape "the stresses of urbanization, modernization, and alienation."
There are at least three conspicuous symbols is An American Tragedy. One of them is the custom-made touring cars that only the rich could afford before the advent of mass production and assembly lines. Another symbol is the power launches that the wealthy young socialites use to speed around on what is virtually their own private blue lake. Both of these symbols suggest leisure, pleasure, freedom from financial care, freedom from work and responsibilities, special privilege, fun by day and romance by moonlight. They symbolize a world that is closed to most people and open to only a special few.
The other conspicuous symbol is the wier-wier bird that haunts the whole harrowing episode in which Clyde Griffiths takes Roberta Alden out on the lake with the intention of drowning her and killing her unborn baby along with her. Dreiser's description of this bird is memorable.
And at one point it was that a wier-wier, one of the solitary water-birds of this region, uttered its ouphe and barghest cry, flying from somewhere near into some darker recess within the woods.
The wier-wier symbolizes death, of course. But it seems to symbolize much more. It is almost like an ancient Greek chorus commenting on this evolving tragedy. It seems to be saying that such scenes as this have been occurring among human beings for as long as humanity has existed. Clyde once loved Roberta. Now he is planning to kill her. These things happen and will keep happening. The bird is older than humanity and has seen it all before.
The words "ouphe" and "barghest" seem strange but also somehow appropriate to the situation. We can almost hear the ouphe and barghest cry even if we can't understand the words without consulting a good dictionary. The cry is a cry of emptiness, loneliness, and despair. It keeps echoing throughout the tragic incident even when it is out of sight. It also seems to be announcing Clyde's guilt to the whole world, foretelling and insuring that he will be caught and punished and that he has been destined to perform the terrible deed and to be executed for it since the beginning of time.
Clyde began his affair with Roberta when he was rowing on a lake and offered her a ride. Now he is terminating it on a lake by killing her and the baby their love affair created. This is the real tragedy in An American Tragedy, not the capture, trial and execution, which are all anticlimactic. The rented rowboats are probably symbolic of the lives of the underprivileged working classes, a far cry from the streamlined power launches that cruise effortlessly on Big Bittern lake in the Adirondacks.