Sherman

The Sherman is a slight variation of the Manhattan. Properly made, it has twice as much vermouth as it does whiskey, which is a little uncommon in a cocktail, but it produces a very nice result.

Sherman

Garnish: Lemon twist.
Stir with ice, and strain into a cocktail glass.
Source: Old Waldorf Bar Days (1931)
You can use bourbon whiskey instead of rye if you need to.