Break out the dictionary: what is the orig. of " shebang'?

I have looked for awhile ( when I can remember it) for the origin of the word " Shebang".

As in: the whole shebang.

I know it means " everything included."

According to this site, here’s the answer.

I also found a nearly identical explanation here.

Dave Wilton says

He then offers that the “whole shebang” is first uttered by me, er uh, Mark Twain in 1869.

And, if you relly want to be confused, read The Maven at http://www.randomhouse.com/wotd/index.pperl?date=20000203

Oh, and I thougt I’d point out that the entry just above “whole shebang” in the latter reference is “whole nine yards,” in which the authors of wordorigins.org cite Cecil’s 1988 book, More of the Straight Dope, so they are clearly people of great discernment.