When was the first pair of pants invented?  Was there a time when there were only pants available?  Did one have to cruise into his or her local general store or textile shoppe and request two pants?

Maybe the concept of a pair of pants came about in a scenario exactly like this…
I recently got a new pair of pants. I walk taller in them.

Old Timey Shopper: Ahoy good sir, might I acquire a pant today?

Shoppe Owner: Really?  Just one pant?  It looks like both of your pants are wearing thin, savvy?

Old Timey Shopper: Savvy.  They are wearing quite thin.  Probably caused by my bristly leg hairs that never cease from scraping the inside of each pant leg.

Shoppe Owner: (look of admiration)

Old Timey Shopper: Wait.  How about I buy a pair of pants and just have my wife, Prudence, sew them together for me in a manly fashion?  I think I might call them…(looks to friend)  Jean!  What should I call two pants I sew together?

Jean: Who me?

Old Timey Shopper: No, the other Jean.

Jean 2: I think you should call them…Franks.

Old Timey Shopper: I don’t know.  That doesn’t seem to fit.  Thanks Jean.  And sorry first Jean — I hope I didn’t jostle you too badly.

Jean: (offers contemptuous gesture)

Shoppe Owner: (looking back to shopper)  I think you are on to something there Levi.  How is your papa, Mr. Strauss?

Old Timey Shopper: He was recently murdered by a posse — wranglers actually.  From the west.  Thanks for causing me to revisit that distressing event.

Shoppe Owner: You are welcome good sir.  Now off with you.  And your pair of pants too.