Cocktail Drink

The earliest definition of cocktail was in the May 13, 1806, edition of The Balance and Columbian Repository, a publication in Hudson, New York, in which an answer was provided to the question, "What is a cocktail?". It replied:
Cocktail is a stimulating liquor composed of spirits of any kind, sugar, water, and bitters—it is vulgarly called a bittered sling and is supposed to be an excellent electioneering potion, inasmuch as it renders the heart stout and bold, at the same time that it fuddles the head. It is said, also to be of great use to a democratic candidate: because a person, having swallowed a glass of it, is ready to swallow any thing else.
Compare the ingredients listed (spirits, sugar, water, and bitters) with the ingredients of an Old Fashioned, which originated as a term used by late 19th century bar patrons to distinguish cocktails made the “old-fashioned” way from newer, more complex cocktails.
The first publication of a bartenders' guide which included cocktail recipes was in 1862 — How to Mix Drinks; or, The Bon Vivant's Companion, by "Professor" Jerry Thomas. In addition to listings of recipes for Punches, Sours, Slings, Cobblers, Shrubs, Toddies, Flips, and a variety of other types of mixed drinks were 10 recipes for drinks referred to as "Cocktails". A key ingredient which differentiated "cocktails" from other drinks in this compendium was the use of bitters as an ingredient, although it is not used in many modern cocktail recipes.