Margarine was originally developed and marketed as a butter substitute, but today it is considered a food in its own right. A scarcity of animal fat (a principal ingredient of butter) in France in the late 1860s prompted the government of Napoleon III (1808-1973) to offer a prize for the best "cheap butter." A French chemist, Hippolyte Mège-Mouriès, conducted a series of experiments and patented his result in 1869. The product consisted of liquid beef tallow, milk, water, and chopped cow's udder, churned into solid form. Mège-Mouriès called his invention oleomargarine: from oleo, the French word for beef fat, and the Greek word margarites, "pearl," because of the product's pearly white color. It was also marketed as "butterine."

From the time margarine was first produced commercially in 1873, the dairy industry bitterly opposed it. Excise taxes were imposed on margarine in the...