Being an authentic American writer is an attitude, a state-of-mind tied up with ambition, scope, the land, the genuine, the world and nature. What are the chief requirements?
1.) Write Simply.
Ernest Hemingway and Raymond Carver are classic examples of the natural American voice. They aren't by any means the only examples. Walt Whitman, Mark Twain, Jack London, Frank Norris, Willa Cather, Gertrude Stein, Sherwood Anderson, F. Scott Fitzgerald, John Steinbeck, Ralph Ellison, and Jack Kerouac are among many representations of the American personality.
2.) Get Into the World.
The classic American writer, such as Herman Melville or Ernest Hemingway, doesn't escape into the mind, but instead plunges outward into the world. Huck Finn escaping from conformity by traveling on a raft down the Mississippi. Often this means projecting the mind onto the world; interior conflicts worked out among the environments of cities or nature.
3.) Write Big.
Think big. Dream big. BE big. Larger-than-life. Like America itself. "The Great American Novel." In poetry, "Howl." Break the mold. Push the art, crudely, madly, exuberantly.