Mournful, because the country is going through the loss of the President after a victorious war.
Bleeding, Captain lies, Fallen cold, Dead, Rise Up, Hear the Bells, I with mournful tread.
" The ship has weather'd every rack, The prize we sought is won," This image of the ship represents the USA/the country, and the prize that was sought was partly stopping slavery and stopping the splitting of the USA.
The author used End Rhyme in the following lines: "O Captain! my Captain! our fearful trip is done,""The ship has weather'd every rack, the prize we sought is won."
The author of the poem uses an extended metaphor throughout the book that shows that the theme of the book maybe the mourning of Abraham Lincoln after he was assassinated.