This article presents the original draft of the Zimmermann telegram from 1917 in facsimile. Its various annotations provide interesting insights, such as the idea to promise California to Japan and instructions concerning transmission and encryption. Further documents clarify how the telegram was sent and put various alternatives suggested in the literature to rest. The political background and fallout in Germany are discussed, as well. Keywords codebook, cryptanalysis, First World War, Room 40, Zimmermann telegram