u/Beneficial_Word_1091

The renowned poem "O Captain! My Captain! » was written by Walt Whitman in 1865. However, we find the same phrase  in two places (— O Captain, my Captain! and Captain! O Captain!) in Chapter CXXXII of Melville's Moby-Dick, written and published in 1851, 14 years before Whitman's poem!

Understanding that Whitman and Melville were two contemporary poets of quite the same age, both of whom lived in or around New York City, and given that Whitman's poem is an allegory of a captain and his ship, and that Melville's book was published 14 years earlier (first famous in England and later in USA) , one might think that Whitman drew inspiration from Melville's novel to write this now-famous line. However, I found no reference to this yet.