By the botanical definition - a ripened flower ovary that contains seeds - a tomato is clearly a fruit.
So Nix wanted his taxes back!
Both sides made heavy use of dictionaries and expert definitions during the hearing.
Definitions of pea, eggplant, potato, turnip, and parsnip were read aloud, probably for the first and last time in Supreme Court history!
The case set a precedent for court interpretation of common meanings (and reinforced the false belief that tomatoes are vegetables!).
Special thanks to @JohnSerwach on the tip for the interesting financial history story!