The American poet who expressed themes of American identity and landscape in his works was Walt Whitman. His landmark collection, “Leaves of Grass,” celebrated the diverse experiences of the American people, blending nature with the human experience. Whitman's bold style and free verse challenged traditional poetic forms, influencing generations of poets. His exploration of democracy, individuality, and the American spirit deepened the connection between art and national identity, making him a foundational figure in American literature.