Henry Watterson (aka "Marse Henry") (1840 - 1921), who founded the Louisville Courier-Jorunal, had it right:

Pluck the mint gently from its bed, just as the dew of the evening is about to form upon it. Select the choicer sprigs only, but do not rinse them. Prepare the simple syrup and measure out a half-tumbler of whiskey. Pour the whiskey into a well-frosted silver cup, throw the other ingredients away, and drink the whiskey.