Orinally a poem post Civil War that makes a metaphor comparing Lincoln to a captian of a boat who dies at the end, the phrase became famous from the 1989 movie "The Dead Poet Society" staring Robin Williams. The whole point of the phrase is that William's character was an English teacher who had his student's address him with that phrase while standing on their desks.
Good morning oh captian, my captian!
47👍 36👎