THORNTON, Ill. (WGN) — A Chicago-area distillery known for its deep ties to Al Capone and the Prohibition era has uncovered a striking new piece of its past, hidden for decades inside its walls.

The Prohibition era lasted from 1920 to 1933 and was one of the most fascinating periods in American history. During this time, the manufacture, sale, and transport of alcoholic beverages were banned ...