Tequila Sour (cocktail)

A “tequila sour” is a cocktail that contains tequila, lemon, sugar, and crushed ice. It’s a similar drink to “border buttermilk,” although that drink sometimes replaces the lemon with lime or lemonade.
       
 
DrinksMixer.com
Tequila Sour recipe
2 oz tequila
juice of 1/2 lemons
1 tsp powdered sugar
1/2 slice lemon
1 cherry
 
Shake tequila, juice of lemon, and powdered sugar with ice and strain into a whiskey sour glass. Add the half-slice of lemon, top with the cherry, and serve.
   
Mixed-Drink.com
Tequila Sour
2 oz Tequila
Juice of 1/2 Lemon
1 tsp Powdered Sugar
Ice
 
Shake ingredients with ice and strain into a glass. Top with a cherry.
 
Wikipedia: Sour (cocktail)
A sour is a traditional family of mixed drinks. Common examples of sours are the Margarita and the Sidecar. Sours belong to one of the old families of original cocktails and are described by Jerry Thomas in his 1862 book, How to Mix Drinks. Sours are mixed drinks containing a base liquor (bourbon or some other whiskey in the case of a whiskey sour), lemon or lime juice, and a sweetener (triple sec, simple syrup, grenadine, or pineapple juice are common).
   
5 March 1944, Nevada State Journal (Reno, NV), pg. S4, col. 5 ad:
Tequila Collins
Tequila Fizz
Tequila Highball
Tequila Gibson
Tequila Side Car
Tequila Martini
Tequila Sour
Distributed by
A. Levy and J. Zentner Co.
 
18 October 1953, Long Beach (CA) Independent Press-Telegram, “Writer Finds Mexico Trip Ideal Vacation Experience” by John S. Knight, pg. A10, col. 2:
BEST DRINK: A tequila sour.
 
18 September 1954, Dallas (TX) Morning News, “Tequila Draws Harsh Epithet” by Sam Acheson, part III, pg. 2:
Mexican bartenders, who claim to be the tourist’s best friend, have come up in late years with what they say is an excellent mixed drink. It is called a Tequila Sour. We wouldn’t know. Local pride leads us to stick to Dr. Pepper.
 
9 June 1956, Oakland (CA) Tribune, pg. 13, col. 2 ad:
Try a
TEQUILA SOUR
with
JOSE CUERVO TEQUILA
One jigger Cuevo Tequila
Juice of 1/2 lemon
Medium teaspoonful of sugar
Shake well with crushed ice
 
11 July 1956, Elyria (OH) Chronicle-Telegram, “Lush Mexican Village” by Whitney Bolton, pg. 38, col. 2:
There is also available what the wine list calls Tequila Sower, but a Tequila Sour after such a dinner is a tranquilizer and it is served icy cold with a tangy rind of green orange in it.
 
17 February 1963, Dallas (TX) Morning News, “Tourists Find Bargain in Rio Grande Valley,” section 4, pg. 7:
But a good tequila sour is about 35c in U.S. money, a quart of tequila less than a dollar.