Which one is an American writer?

• Walt Whitman, in full Walter Whitman, is an American poet, journalist, and essayist whose verse collection Leaves of Grass, first published in 1855, is a landmark in the history of American literature.
• His Notable Works:
- Calamus,
- Crossing Brooklyn Ferry,
- Democratic Vistas,
- Drum-Taps,
- I Sing the Body Electric,
- O Captain! My Captain!,
- Song of Myself,
- Specimen Days & Collect,
- Starting from Paumanok.
Source: Encyclopedia of Britannica.