Angostura Aromatic Bitters
Angostura Aromatic Bitters is a popular brand of cocktail bitters which was first developed in 1824 by Johann Gottlieb Benjamin Siegert as a health tonic. Originally, the product was produced in the town of Angostura, from which the product was named (and not because it included the bark of the Angostura tree).
While simply one-of-many cocktail bitters in use prior to 1920, after American Prohibition the number of available cocktail bitters gradually fell off, until Angostura was almost (but not quite) the only available brand. Since 2005, the number of companies making cocktail bitters has increased greatly. There are now more brands, types, and styles of cocktail bitters available then at any other time in history.