Maybe the resident historians can help out here.

I have heard, and now I don't remember where, that aging
whiskey, and aging whiskey in a charred barrel were
discovered by circumstance. Here's the myth:

Charring a barrel was a common way to clean and
sterilize a previously used barrel. To remove the taste
of pickles or fish, the barrel was burnt and scraped.

Whiskey was often stored in new but sometimes in used barrels.

As the frontier was opening, whiskey was beginning to be shipped
long distances. Whiskey from Pennsylvania and Kentucky
would spend months or years travelling down the Mississipi
and out by wagon. The used, charred, barrels were often sent
to this less prestigious "export" market.

By the time the whiskey reached its destination, it had
spent a good deal more time in the charred wood than it
would have if consumed in local markets.

It became apparent that the whiskey from charred barrels
were preferable to that in uncharred barrels, and the
longer in the barrel the better.

So we can thank the pioneer's thirst and Manifest Desitny for
the current glory of our ambrosia.

While our European forebears gave birth to whiskey, the
perfection is wholly American. In glorious
American fashion, we have taken greatest advantage of

Can anyone confirm if this story is true, in any part?

When did aging and the use of charred barrels become
a requisite part of whiskey production?