I had my dream, I held your hand on that broad avenue
Jack dream’t of being with the girl.
It could be possible that this song is also about Allison Mosshart of The Dead Weather. A possible affair causing the end of his marriage. A Blunderbuss is after all a gun that can blow up in your face.
To help improve the meaning of these lyrics, visit "Blunderbuss" by Jack White Lyrics and leave a comment on the lyrics box