Rye whiskey, Peychaud's bitters, and an absinthe-rinsed glass — America's oldest cocktail, New Orleans 1838.
The Sazerac has a strong claim to being America's oldest cocktail, originating around 1838 at the Sazerac Coffee House in New Orleans. It was originally made with Sazerac-de-Forge et Fils Cognac, which Antoine Amédée Peychaud (a Creole apothecary) mixed with his proprietary bitters and sugar. A phylloxera outbreak in the 1870s decimated French Cognac supplies, and American rye whiskey replaced it.
The absinthe rinse is not optional and not interchangeable. The anise aroma from the absinthe is the first thing that hits your nose as you drink. Without it, it's a rye old fashioned with Peychaud's bitters — a good drink, but not a Sazerac. Peychaud's bitters themselves are also essential: they have a distinctive anise-cherry-bergamot character that Angostura bitters don't replicate.
Use VSOP Cognac instead of rye whiskey — the original 1838 recipe. Softer, fruitier, and more complex. Harder to find the character than with rye.
Use Herbsaint (an anise liqueur made in New Orleans by Sazerac Company) instead of absinthe. More traditional and slightly lighter on the anise.
Replace rye with mezcal. The smoke and Peychaud's cherry note make an unexpected but compelling combination.