Answer:
It was written in memory of someone who died.
Step-by-step explanation:
An elegy is a poem which is written in a sad tone especially reflecting on the death of someone special. It is written to lament for the person who is dead and who is very dear to the poet. The poem "O Captain! My Captain" is an elegy written by Walt Whitman. He wrote the poem to lament the death of Abraham Lincoln, the President of America. The poem is about the sorrow and sadness which had come in the lives of the people after Lincoln's death.