Due to its size, this treatise on the origin of the cocktail will be published in several parts, as follows:
In “The Vocabulary of the Drinking Chamber”, Henry Louis Mencken described in 1948 the problem of not really knowing from where the cocktail got its name. He had collected between 40 and 50 different theories. [1-21] We do not want to list them all, nor do we want to go into detail about them. Nevertheless, we have compiled a few of them below.
Betsy Flanagan is said to have owned a tavern in Four Corners, Elmsford or Yorktown, which was frequented by American and French soldiers. One evening in 1779, she had American and French officers as guests and served them a rooster that had previously been stolen by a hated English neighbour. She then served them a punch and decorated the glasses with the rooster’s feathers. The officers are said to have then said, „Let’s have some more Cocktails“ and „Vive le cocktail“. [1-21]   
However, Betsy Flanagan is only an invented character from James Fenimore Cooper’s novella “The Spy: A Tale of Neutral Ground”, and she is probably based on Catherine Hustler, in whose tavern he wrote the novella. [3-189]    
So it’s no surprise that some credit Catherine Hustler with the invention of the cocktail. She and her husband Thomas ran a tavern in Storm’s Bridge, now called Elmsford, in New York State between 1776 and 1783. It was there that James Fenimore Cooper wrote his novella “The Spy: A Tale of Neutral Ground”, and the landlady is said to have been the model for Betsy Flanagan. [3-188]    But unfortunately there is no evidence that Catherine Hustler invented the cocktail.
Coctel or Xochtil
The invention of the cocktail is also attributed to another woman. It is said to be named after an Aztec princess called “Coctel” or “Xochtil”. This princess is said to have been the daughter of King Axolotl VIII and to have handed a mixed drink to a general of the American southern states during peace negotiations at the beginning of the 19th century. [1-21]  But there is no evidence for this story, and the author of the same, Harry Craddock, also hints at it.  
But the cocktail is also said to have been invented by Colonel Carter of Culpeper Court House in Virginia. At “The Cock and Bottle” Inn, which bore a resemblance to an old English tavern and had a cock and bottle as a pub sign, he received a muddy drink from the tap of a barrel, the “cock”. He did not like this at all, threw it on the floor and exclaimed that after such a thing he would only drink home-brewed cocktails: “Hereafter I will drink cocktails of my own brewing”, and so he was inspired to mix Holland Gin, that is Jenever, with bitters, sugar, the oil of a lemon zest, and so it came about that the first cocktail was drunk. 
Antoine Amedée Peychaud
Another opinion traces the origin of the cocktail to New Orleans. There, they say, the apothecary Antoine Amedée Peychaud, inventor of Peychaud’s Bitters, served his bitters with cognac in an egg cup, known in French as a “coquetier”. This name of the cup, it is said, would then have changed to “cocktail”. This is said to have been around 1795. Unfortunately, this is contradicted by the fact that Peychaud’s Bitters were probably not produced before 1830. [1-22]      
Wine-based mixed drink from Bordeaux.
Alternatively, the term “cocktail” is said to have been derived from the French word “coquetel”. This is said to have meant a wine-based mixed drink from the Bordeaux region. Since the Americans were supported by the French army during their war of independence, it is said that they got to know this drink from the French and adopted the name. [4-16] 
However, the name is also said to refer to the morning ingestion of a medicinal, alcoholic drink after being awakened by the cockcrow.  Alternatively, it is believed that the drink was consumed in the morning and acted like the wake-up call of a cock greeting the first light of day. 
The explanation that drinks of various kinds were mainly served from barrels in the 18th and 19th centuries goes in a completely different direction. The stopper of these barrels was called a “cock”, and the last remaining liquid in the barrels was called a “tail”. These remnants, the “tailings”, were served at a reduced price in the pubs, and so the two terms were combined and these poured out remnants were called “cocktails”.  
A similar interpretation refers to a large, hollow ceramic cock that is said to have been present in American bars. Bartenders would have poured leftover drinks into it. The resulting mixture was offered at a special price and tapped from the cock’s tail, which is why these mixtures were also called “cocktails”.    There is no historical evidence for this theory. 
Escaped fighting cock
There are also numerous anecdotes linking the cocktail to cockfighting. According to one theory, a Washington innkeeper once lost his best fighting cock. This was brought back by a soldier, and the latter received a refreshing mixed drink in return. This was said to be as colourful as a cock’s tail. This drink was therefore called a “cocktail”. 
A similar derivation refers to the same reasoning, but without bringing the runaway cock into play. The “cocktail” was not mixed, but layered, which is possible because of the different density of liqueurs without the layers mixing. Seen from the side, the different liquors lying on top of each other reminded one of a colourful cock’s tail.  But one must object here that mixed drinks were by no means colourful in the 1800s, and layered drinks also only came into fashion much later. Moreover, such layered drinks are not cocktails, but were classified as a separate category, a pousse café. 
It is also said that the name refers to the cockfights that were widespread in the south of the USA. There, the owner of the winning cock had the right to pull out the tail feathers of the killed, defeated cock. These, it is said, were then attached to his drink as decoration, and people drank “on the cock’s tail”.    However, there is no historical evidence for this. 
Strengthening drink for cocks
Another theory also refers to the cockfights and says that the cocks were given the so-called “cock ale” or “cock bread ale” to strengthen their fighting power. This was an infusion of herbs and roots soaked in ale.  However, there is no evidence for this derivation. 
According to another derivation, “cock ale” was a name for a certain type of drink in the 1800s that can be traced back to 1648. In Scotland, a potion of this name is said to have been prepared by placing the crushed bones of a cock with nutmeg, sultanas, cloves and other spices in a linen sack in a barrel of ale and letting it steep for several days.  
We have already discussed the references to horse breeding in detail. Related to this, but probably not quite accurate, is this derivation of the term: In the 18th and 19th centuries, draught horses had their tails trimmed to prevent them from getting caught in the harness. These horses were called “cock-tailed” because their tails stuck up in the air like a cock’s tail. Basically, all non-purebred horses had their tails trimmed, and so the term “cocktail” became established for these horses. This designation of a “mixed-breed horse” then also came to mean a “mixed-breed drink”, as a designation for a spirit that was not consumed “purebred”, but diluted, sweetened and mixed with bitters. 
- Christine Sismondo: The Cocktail. The first amendment and the professionalization of the industry. In: Mixologist. The Journal of the American Cocktail. Volume 2. Published by Jared Brown. ISBN 0-9760937-1-5. Mixelany, 2006.
- Helmut Adam: Der Ursprung des Wortes Cocktail. In: 200 Jahre Cocktail. 1806-2006. Mixology, 2006.
- Anistatia Miller & Jarred Brown: Spirituous Journey. A history of drink. Book one: From the birth of spirits to the birth of the cocktail. ISBN 0-9760937-0. Mixellany, 2009.
- Anistatia Miller & Jarred Brown: Spirituous Journey. A history of drink. Book two: From publicans to master mixologists. ISBN 0978-1-907434-06-8. Mixellany, 2009.
- http://www.creativshake.com/geschichte/herkunft-des-wortes-cocktail: Herkunft des Wortes Cocktail.
- http://www.lebouquet.org/cocktail-woher-stammt-der-name.html: Woher hat der Cocktail seinen Namen? Von Juliane.
- https://de.wikipedia.org/wiki/Cocktail: Cocktail.
- https://books.google.de/books?id=OKcyDwAAQBAJ&printsec=frontcover&hl=de&source=gbs_ge_summary_r&cad=0#v=onepage&q=carter&f=false: Joseph L. Haywood: Mixology – The Art of Preparing all Kinds of Drinks. Read Books Ltd, 2017.
- http://www.straightdope.com/columns/read/1765/whats-the-origin-of-cocktail: What’s the origin of “cocktail”? 17. April 2000.
- http://www.saveur.com/how-the-cocktail-got-its-name: Ancient Mystery Revealed! The Real History (Maybe) of How the Cocktail Got its Name. By David Wondrich, 14. January 2016.