US use of johnson

[airbolt]

Most euphemisms for private parts have a fairly obvious origin. However the use of "johnson" for the male member rather foxes me.

Any ideas on the origin of this US term?

[Quizmonster]

In 1930s USA, a Johnson bar was a long, heavy lever used to reduce the motion of a steam locomotive. Perhaps the name for a penis was related to the four words in italics above!
Here in Britain, 'John Thomas' - equally mysteriously - used to mean the same thing.

[Quizmonster]

The earliest recorded use of the phrase John Thomas, as a matter of interest, in the sense of male member, dates back to the 1870s. It was probably just an elaboration on the fact that - for centuries prior to that - servants were often called 'Johns' and bearing in mind that one measning of �to serve' means to have sex with.
Click here for more information, including a reference to a possibly real historical John Thomas!

[Quizmonster]

Sorry, the link didn't work. Let me try again...Click here.