The drink recipe as described above is the original Brandy Fix. Add a teaspoon of Orange Curacao for the fancier version that followed later during the Golden Age of cocktails. That version is akin to a Sidecar except on the rocks and with a more dominant brandy profile with the orange liqueur playing a minor supporting role. Back off a little on the sugar if using Curacao.
Brandy at the time this drink was invented was one of the top base spirits in use if not the most popular. It has since fallen by the wayside as other spirits have surged in popularity. In some cases this is because of shortages or scarcity of French brandy during wars (rum made progress in American mixed drinks because of this). More recently brandy took a hit due to a general change in the preferences of the drinking public for cleaner, lighter spirits (such as vodka).
The current cocktail Renaissance has reversed this trend somewhat as brandy and Cognac come back into the fold as cocktail ingredients. This is a good thing for drinks like the Brandy Fix.