Ich bin ein Berliner
The phrase "Ich bin ein Berliner" (English: "I am a Berliner") was used by President Kennedy during a speech on August 13th, 1961 in Berlin after the Berlin Wall was erected. The intent was to declare that every free person was united together in purpose in Berlin.
The speech is regarded as one of the most important and powerful speeches given in the 20th century. Listening to it, even today, one cannot help but marvel at the power and the danger inherent in living during the Cold War.
 Urban legend
Kennedy was given a proper and grammatically correct statement to say, but many English-speaking people, aware that German generally doesn't use the indefinite article before a profession, or place of origin, presumed that the statement must be wrong. And upon discovering that there is a donut called "ein Berliner", they announced that Kennedy accidentally said "I am a jelly donut" instead of "I am a Berliner."
This is, in fact, an urban legend. The term "Berliner Pfannkuchen" was not widely used until after Kennedy's speech. At the same time as the "Berliner" donut was becoming better known, the Berliner Dampfbäckereien (Berlin steam bakeries) came into business and registered the trademark for "Berliner." Thus, only bakers who were trained in this specialty, and from Berlin, were permitted to use the term "Berliner."
All of that information aside, the sentence is also very clearly grammatically correct to anyone who speaks German fluently. The use of "ein" in the sentence was for a dramatic, strengthening effect. However, as this story is already very widespread, there is a lot of false history maintaining the faulty belief.
It should also be noted that the crowd roared, not with laughter, but with excitement and cheering. If anyone there thought it was funny, it was not caught on tape. There was laughter slightly later, when Kennedy thanked his translator for translating his German into German.
 Rural legend
- "Ich bin ein Springfielder" - Mayor "Diamond" Joe Quimby
- ↑ Nuh-uh, Eddie Izzard said it so it must be true.
- ↑ "Frankfurter" was widely recognized, of course, as another name for a hot dog. "Hot dog" gained popularity during the World Wars to avoid mentioning the German city.
- ↑ Renamed "liberty steak," for similar reasons, but the renaming did not catch on.