Zimmermann probably sent lots of telegrams in his life, but this is by far the most consequential, so they named it after him. It's The Zimmermann Telegram. (Don't forget that extra N in his last name, dudes.)

He undoubtedly wished that he could have his name attached to something less embarrassing for all of history, but he should have thought of that before he hit "send"…or whatever one does to make the telegram go to the place.