If you read poetry, there are many great American poets to choose from.
I recently read a list that recommended the following: Walt Whitman, Emily Dickinson, Ralph Waldo Emerson, Henry Wadsworth Longfellow, William Cullen Bryant, and Henry David Thoreau.
Among modern and contemporary poets, the list included Maya Angelou, Amiri Baraka, Louise Bogan, Robert Bly, E. E. Cummings, T. S. Eliot, Jane Hirshfield, Langston Hughes, W. S. Merwin, Edna St. Vincent Millay, Mary Oliver, Wallace Stevens, and William Carlos Williams.
I don’t think Maya Angelou, Amiri Baraka, Jane Hirshfield, or Louise Bogan belong on this list. They are successful writers among academics and, in Angelou’s case, among the popular crowd but they are not great writers.
Missing from the list are Ezra Pound, Robert Frost, Robert Penn Warren, John Ashbery, Robert Lowell, and Charles Simic.