Who is not an American poet?

Robert Browning, (born May 7, 1812, London—died Dec. 12, 1889, Venice), a major English poet of the Victorian age, noted for his mastery of dramatic monologue and psychological portraiture.
Among Browning’s important publications are:
- The Ring and the Book (1868–69),
- Pauline (1833),
- Bells and Pomegranates (1841–46),
- My Last Duchess,
- Men and Women (1855),
- Dramatis Personae (1864),
- Asolando (1889).

Robert Frost, Ezra Pound, Walt Whitman are American Poets.

Source: Britannica and Goodreads