Read this line from "O Captain! My Captain!". The ship has weather'd every rack, the prize we sought is won; What does “the prize we sought is won” refer to? They won a game. They found a lost treasure. They won an election. The North has won the Civil War.

The correct answer is D. The North has won the Civil War.

The entire poem by Whitman is actually an extended metaphor in which Captain represents Abraham Lincoln and the poem is about his death. He writes about how he's calling his captain to celebrate that they won the war but he finds that his captain has died, which refers to the assassination of Lincoln which happened quickly after the war ended.