The battle over margarine's place in the country was seriously debated after its invention in 1870. The agricultural community, led by Wisconsin's strong dairy interests, saw the artificially produced margarine as an intruder on the market and the rural way of life.

In 1895, just 47 years after it became a state, Wisconsin passed its ban on the sale or use of margarine colored to imitate butter. The pressure to repeal that ban grew in the 1960s as Wisconsin was left as the only state with the prohibition. Residents were getting around the law by buying margarine in neighboring states just across the border.

Then state-Sen. Martin Schreiber, a 26-year-old Democrat who went on to serve as acting governor in the 1970s, proposed doing away with the ban in 1965 but he said rural Republicans bottled it up. So he came up with a creative way to make his case: a blind taste test.

One of butter's most ardent supporters, Republican Sen. Gordon Roseleip, happily took the taste test and promptly chose margarine as better tasting. His flub made national news.

"That was the beginning of the end," Schreiber said.