One of #Walt_Whitman's most famous #poems is "O Captain! My Captain!" This poem was written as an elegy for Abraham Lincoln after his assassination and is a departure from Whitman's usual free verse style. In the poem, the speaker mourns the death of the beloved captain, who represents Lincoln, as a tragic loss. The poem reflects the nation's collective grief and the sentiment of a ship (representing the United States) returning to the safety of the harbor after a perilous journey, only to find the captain dead. It's a poignant and emotional expression of the deep sorrow felt by many Americans upon Lincoln's assassination.