Used for money

Hello,

Hamilton, with characteristic vigor, sought additional internal revenue and in 1791 secured from Congress an excise tax on a few domestic items, notably whiskey. The new levy of seven cents a gallon was borne chiefly by the distillers who lived in the backcountry, where the wretched roads forced the farmer to reduce (and liquify) bulky bushels of grain to horseback proportions. Whiskey flowed so freely on the frontier in the form of distilled liquor that it was used for money.

The American Pageant by Thomas A. Bailey.

How can I interpret “it was used for money” ? Does it mean using distilled liquor as their currency?