Sentence:  Still more jealous bitterness was engendered by the O ' Banion gang 's seizure from a West Side marshalling yard of a freight-car load of Canadian whisky worth $ 100000 and by one of the biggest coups of the <WSD>Prohibition</WSD> era - the Sibley warehouse robbery , which became famous for the cool brazenness of the operation . 
Meaning of the word marked with <WSD> tags:  the period from 1920 to 1933 when the sale of alcoholic beverages was prohibited in the United States by a constitutional amendment