The Brandy Cocktail is a true classic which dates back to Jerry Thomas' 1862 bartending guide How To Mix Drinks or The Bon-Vivant's Companion and beyond. Back then, his recipe included gum syrup and Bogart's bitters as well as the orange liqueur and brandy that Craig E. cited above from Harry Craddock. Here's another recipe quoted from Robert Vermeire's 1922 book Cocktails - How To Mix Them:
Fill the bar glass half full of broken ice and add:
1 or 2 dashes of Angostura Bitters.
3 dashes of Curacao.
1/2 gill of Brandy. (2 oz)
Stir up well, strain into a cocktail-glass, add Olive or cherry, and squeeze lemon peel on top. A little dash of Absinthe improves this cocktail, which is also often made with equal parts of Brandy and French Vermouth. It should be noted that all plain cocktails are made the same way as the Brandy Cocktail. The base liquor can be either Gin, Whisky, Rum, Vermouth, Sherry, etc., and the cocktail is therefore named according to the base liquor.