The French 75 was invented in France at the famous New York Bar in Paris in 1915. At that time Europe and especially France 
was knee deep in the horrors of World War I, and that was foremost on just about everyone's mind.
The barman (and later owner) of the New York Bar, Harry MacElhone came up with the drink that someone remarked, "kicked like a 75mm howitzer."
Obviously the name stuck.
It made its way to America and became a very popular drink during prohibition, probably because of its base, gin, which was cheap and popular in the speakeasies of the time.
We ran into the French 75 at the Green Door Tavern in Chicago, IL. The Green Door Tavern is a well-preserved example of a 1920's speakeasy, and this is probably a fitting drink to have there. The drink itself is not sweet at all, more on the sour side but bearable. It does have a bit of fizziness but not much, and it will put you on the floor if you have too many, trust us!
French 75 Recipe
Starting with ice in a rocks glass
1 1/2 oz of quality gin
1/2 oz simple syrup
1/2 oz lime juice/sour mix
1 oz dry champagne
Let it settle and garnish with cherry and lime. Enjoy!