Coffee : cup of joe?

[Steve69]

Does anyone know where the American phrase ' a cup of joe' referring to a cup of coffee came from?

[geofbob]

According to one dictionary, the American slang term "joe" for coffee originated in WWI, and had its origins in a then popular song - which would probably be considered racist these days - called "Old Black Joe" by Stephen Foster, a renowned song-writer. The term possibly caught on because it had roughly the same sound as another slang word for coffee, "java", after the place much coffee came from in the 19th century. Perhaps "java" was slang for white coffee, and "joe" for black.

[sft42]

Altenative theory: During WW 1 their was a navy captain with the first name Joseph. He was distressed to see that his crew was getting hammered on rum while aboard ship. He made alcohol off limits and encouraged the crew to get their kicks from coffee. Thus the ship hands began asking for a cup of "Joe". The rest is history...here's a link backing that theory http://www.jafi.org.il/aliyah/dept/aliyon/aliyon9/
prof_dov.html

[Quizmonster]

Click http://www.randomhouse.com/wotd/index.pperl?date=2
0000120 for an American idiom-website's ideas on the subject. (They're very much the same as Geofbob's response above, but provide a little more information.)