Why and when did "crack" come to mean "tell"?

There is a difference between "Crack" and "Tell" when it comes to jokes. To crack a joke is to make an original witty remark (i.e. something that, in context, is funny, but would not necessarily stand alone as humor); to tell a joke is to relate a bit of humor that is expected to be received well by your audience.

A sample of the difference:

Your friend says "Hey, did you hear this news story? A bookie in Vegas was attacked by one of his customers."

You say "Wow, I guess they were really at odds with each other. Baaahaha!"

You have just cracked a joke. A small, lame pun-based joke, to be sure, but still.

Your friend says "How many mice does it take to screw in a light bulb? Two, but how did they get into the lightbulb in the first place?"

Your friend has just told a joke.

You will also see (especially in the UK and Ireland) "cracking on" for telling a story or speaking extendedly, and "enjoying the crack" for getting together with friends to talk. That one is often spelled "craic" but Wikipedia is insistent it came from English crack: http://en.wikipedia.org/wiki/Craic.

I would say that "crack" (in this context) is a FORM of telling, rather than "telling" itself.

You can "tell" a joke, with a straight face and a monotone and not get any laughs.

To make a joke funny, you need to "crack" it as you "tell" it. Think of cracking open a nut. Or popcorn "crackling" with butter over an open fire.

The term 'crack' appears in many contexts where both quickness and accuracy are involved, such as 'crack shot' or 'crackerjack wit'. I suspect it's an onomatopoeia thing due to the plosive 'k' sounds at both the beginning and end of the word sounding like the 'crack of a whip'.