Add the whiskey, vermouth, and bitters to a glass or cocktail shaker with ice.
Stir for 15 seconds to chill.
Strain the drink into a rocks glass with a large ice cube or a chilled stemmed glass without ice.
Rub the orange peel around the rim, then garnish the drink with the orange peel and a maraschino cherry.
Serve your Manhattan drink immediately after preparing it. Enjoy!