Its origins are subject to speculation. It has been proposed that it gets its name from either the South Side district of the city of Chicago, Illinois, or from the Southside Sportsmen's Club on Long Island.
The drink may have been the preferred beverage of Al Capone, whose gang dominated Chicago's South Side. The gin imported by Capone's rivals on the North Side of Chicago was smooth, and usually consumed with ginger ale. However, the gin consumed by Al Capone's gang had a rougher finish, and required more sweeteners to make it palatable. Thus the South Side was born.
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4 lemon wedges
2 to 3 teaspoon granulated sugar
4 to 5 fresh mint leaves
2 1/2 ounces Gin