Complex sentence: A speakeasy, also called a blind pig or blind tiger, is an establishment that illegally sells alcoholic beverages which came into prominence in the United States during the Prohibition era (1920--1933, longer in some states).
Split into simpler sentences: A speakeasy, also called a blind pig or blind tiger, is an establishment that illegally sells alcoholic beverages. Such establishments came into prominence in the United States during the Prohibition era (1920--1933, longer in some states).