"Our fearful trip is done" is a phrase from the poem "O Captain! My Captain!" by Walt Whitman. It refers to the end of a trip that was frightening. The phrase is often interpreted as referring to the end of the American Civil War, with the captain symbolizing Abraham Lincoln, and the trip symbolizing the war and its challenges. The poem mourns the loss of Lincoln, who was assassinated shortly after the end of the war. The phrase "our fearful trip is done" expresses a sense of relief that the war has ended, but also a sense of sadness for the loss of the captain.