Chicago
The ratification of the 18th amendment to the Constitution in 1919 made the production and sale (including exportation) of alcoholic beverages illegal in the United States. This ushered in the beginning of what is known as the Gangster Era, a time that roughly spans from 1919 until 1933 when Prohibition was repealed. The 1920s saw gangsters, including Al Capone, Dion O'Banion, Bugs Moran and Tony Accardo battle law enforcement and each other on the streets of Chicago during the Prohibition era. Chicago was the location of the infamous St. Valentine's Day Massacre in 1929, when Al Capone sent men to gun down members of a rival gang, North Side, led by Bugs Moran.
Jury nullification in the United States
During the 19th and 20th centuries, especially in the 1950s and '60s civil rights movement era, some all-white juries acquitted white defendants accused of murdering blacks; however, the problem according to some scholars was: "...not in jury nullification, but in jury selection. The jury was not representative of the community..." During Prohibition, juries often nullified alcohol control laws, possibly as often as 60% of the time because of disagreements with the justice of the law. This resistance is considered to have contributed to the adoption of the Twenty-first Amendment repealing the Eighteenth Amendment which established Prohibition.