The Manhattan is New York city's signature cocktail and a whiskey lovers dream. The Manhattan is a cocktail made from whiskey, sweet vermouth, and bitters and it's invention is claimed as far back as 1870.
If you cannot find angostura bitters, than a more common botanical bitters are a suitable substitute.
Please note that the units field is an estimation, and will vary depending on the type and quantity of alcohol used. Please drink responsibly and legally.