Which of the following is not Walt Whitman's poem?

Walt Whitman(1819-1892): American poet, journalist, and essayist.
His famous works:
- A Passage To India (poem),
- Leaves of Grass,
- Drum-Taps,
- O Captain! My Captain!,
- Songs of Myself etc.

‘Mending Wall’ is a famous poem of Robert Frost.

Source: Britannica.com