 The second season, subtitled "Chicago", focuses on the origin of Al Capone, his Chicago Outfit, and their expansion into the Midwestern U.S.

On January 10, 2015, AMC ordered the series as a "special event" miniseries to air in mid-2015.On July 31, 2015, two weeks after the series premiere, AMC renewed it for a second season to air in mid-2016.The received mixed responses from television critics and a Metacritic score of 59 out of 100, based on six reviews, indicating "mixed or average reviews".