, 1785 : A note from a "Baltimorean" to a Maryland legislator about "The Act for Founding a College on the Western Shore." Two clauses specifically mention whiskey and require that the retailer has a license to sell it.
Source: Maryland Journal. (Baltimore, Maryland) • 08-16-1785 • Page [2]

, 1786 : Six years before Hamilton's famous Whiskey Tax, Frederick, Maryland needed to impose retailer rules! Looks like there were already a fair number of distillers in Western Maryland and the local government needed to monitor expansion.
Source: The Maryland Chronicle or the Universal Advertiser (Frederick, Maryland) • 03-22-1786 • Page [1]

, 1803 : Maryland Whiskey was a distinct product and famous up and down the east coast. This note from the Evening Standard in New York advertises 30 Gallons of Maryland Whiskey for sale.
Source: The Evening Post. (New York, New York) • 05-24-1803