The Man O' War is named for the greatest American racehorse of the twentieth century — 20 wins in 21 starts, retired to stud in Kentucky in 1920 — and it is, fittingly, a bourbon drink with unusual polish. Orange curaçao and sweet vermouth split the modifier duties while lemon keeps the sweetness honest: half sour, half Manhattan, and smoother than a drink this strong has any business being.
Half sour, half Manhattan — like its namesake, it covers ground faster than it looks like it's moving.
History
The drink surfaces in the 1920s, contemporary with the horse's fame, and is usually traced to Kentucky — one persistent account ties it to the circle around the horse's owner, Samuel Riddle, but the documentation is thin and we'll flag it as tradition rather than fact. What's solid is the drink's survival in mid-century bar guides and its revival alongside the rest of the whiskey canon.
Structurally it's kin to the Ward 8 and the Bourbon Sidecar: whiskey sours that traded plain sugar for something with an opinion.
The Spec
Two parts bourbon, one part orange curaçao, with sweet vermouth and lemon in equal smaller measure. Shaken, served up, orange twist. The curaçao is generous by modern standards — that's the period talking, and it works.
Curaçao Quality Shows
At a full ounce, the orange liqueur is a co-star, not a seasoning — a proper brandy-based curaçao or a dry triple sec keeps the drink from going syrupy. Bottom-shelf orange liqueur is the most common way this drink goes wrong.
Bourbon With Backbone
A 100-proof or bottled-in-bond bourbon holds the center against all that orange. At 80 proof the drink is pleasant but loses the race.
Bottom Line
The Man O' War is one of the best obscure bourbon drinks of its era — richer than a sour, brighter than a Manhattan, and a guaranteed conversation starter for racing fans. Pour it strong; the horse would expect nothing less.