Question: Boardwalk Empire was inspired by a book about a political boss who was convicted and imprisoned in what year?

Context paragraphs:
Boardwalk Empire (season 3): The third season of the HBO television series "Boardwalk Empire" premiered on September 16, 2012 and concluded on December 2, 2012, consisting of 12 episodes.  The series was created by Terence Winter and based on the book "Boardwalk Empire: The Birth, High Times and Corruption of Atlantic City" by Nelson Johnson.  Set in Atlantic City, New Jersey, during the Prohibition era, the series stars Steve Buscemi as Enoch "Nucky" Thompson (based on the historical Enoch "Nucky" Johnson), a political figure who rose to prominence and controlled Atlantic City, New Jersey, during the Prohibition period of the 1920s and early 1930s.  Taking place 16 months after season two, the third season begins on New Year's Eve 1922 and concludes in June 1923.  The third season was released on DVD and Blu-ray in region 1 on August 20, 2013.

Enoch L. Johnson: Enoch Lewis "Nucky" Johnson (January 20, 1883 – December 9, 1968) was an Atlantic City, New Jersey political boss, Atlantic County Sheriff, businessman, and racketeer.  He was the undisputed "boss" of the political machine that controlled Atlantic City and the Atlantic County government from the 1910s until his conviction and imprisonment in 1941.  His rule encompassed the Roaring Twenties when Atlantic City was at the height of its popularity as a refuge from Prohibition.  In addition to bootlegging, his organization also was involved in gambling and prostitution.

Boardwalk Empire (season 5): The fifth and final season of the HBO television series "Boardwalk Empire" premiered on September 7, 2014, and concluded on October 26, 2014, consisting of 8 episodes.  The series was created by Terence Winter and based on the book "Boardwalk Empire: The Birth, High Times and Corruption of Atlantic City" by Nelson Johnson.  Set in Atlantic City, New Jersey, during the Prohibition era, the series stars Steve Buscemi as Enoch "Nucky" Thompson (based loosely on the historical Enoch "Nucky" Johnson), a political figure who rose to prominence and controlled Atlantic City, New Jersey, during the Prohibition period of the 1920s and early 1930s.  The fifth season takes place between April and October 1931, seven years after the previous season, during the Great Depression, with flashbacks to 1884 and 1897 detailing Nucky's childhood and young adulthood.  The fifth season was released on DVD and Blu-ray in region 1 on January 13, 2015.

List of Boardwalk Empire episodes: "Boardwalk Empire" is an American television series created by Terence Winter and based on the book "Boardwalk Empire: The Birth, High Times and Corruption of Atlantic City" by Nelson Johnson.  The series debuted on September 19, 2010, and concluded on October 26, 2014 on HBO, consisting of 56 episodes over five seasons.  Set in Atlantic City, New Jersey, during the Prohibition era, the series stars Steve Buscemi as Enoch "Nucky" Thompson (based on the historical Enoch L. Johnson), a political figure who rose to prominence and controlled Atlantic City, New Jersey, during the Prohibition period of the 1920s and 1930s.  The series received widespread critical acclaim, winning various awards including Golden Globe Awards for Best Drama Series and Best Actor in a Television Drama Series for Buscemi for its first season.

Boardwalk Empire (season 1): The first season of the HBO television series "Boardwalk Empire" premiered on September 19, 2010 and concluded on December 5, 2010, consisting of 12 episodes.  The series was created by Terence Winter and based on the book "Boardwalk Empire: The Birth, High Times and Corruption of Atlantic City" by Nelson Johnson.  Set in Atlantic City, New Jersey, during the Prohibition era, the series stars Steve Buscemi as Enoch "Nucky" Thompson (based on the historical Enoch L. Johnson), a political figure who rose to prominence and controlled Atlantic City, New Jersey, during the Prohibition period of the 1920s and 1930s.  The first season takes place between January and November 1920, beginning with the start of national prohibition and ending with the 1920 presidential election.

Patrick Nash: Patrick A. Nash (March 2, 1863 – October 6, 1943) was a political boss in the early and mid-twentieth century in Chicago, which is in Cook County, Illinois, United States.  He was in large part responsible for consolidating elements of the Cook County Democratic Party into a political machine.  He evolved from a local sewage contractor to a political boss by carefully selecting his political allies.  His prominence stems from the death of Anton Cermak and his political career is intertwined with that of Edward Joseph Kelly.  The success of this machine was attributed to its decision to be more inclusive than its predecessors.  This meant that Nash had success at dealing with a variety of politicians such as William L. Dawson.

Boardwalk Empire (season 2): The second season of the HBO television series "Boardwalk Empire" premiered on September 25, 2011 and concluded on December 11, 2011, consisting of 12 episodes.  The series was created by Terence Winter and based on the book "Boardwalk Empire: The Birth, High Times and Corruption of Atlantic City" by Nelson Johnson.  Set in Atlantic City, New Jersey, during the Prohibition era, the series stars Steve Buscemi as Enoch "Nucky" Thompson (based on the historical Enoch L. Johnson), a political figure who rose to prominence and controlled Atlantic City, New Jersey, during the Prohibition period of the 1920s and 1930s.  The second season takes place between February and August 1921.  The second season was released on DVD and Blu-ray in region 1 on August 28, 2012.

Boardwalk Empire (season 4): The fourth season of the HBO television series "Boardwalk Empire" premiered on September 8, 2013, and concluded on November 24, 2013, consisting of 12 episodes.  The series was created by Terence Winter and based on the book "Boardwalk Empire: The Birth, High Times and Corruption of Atlantic City" by Nelson Johnson.  Set in Atlantic City, New Jersey, during the Prohibition era, the series stars Steve Buscemi as Enoch "Nucky" Thompson (based on the historical Enoch L. Johnson), a political figure who rose to prominence and controlled Atlantic City, New Jersey, during the Prohibition period of the 1920s and early 1930s.  The fourth season takes place between February 1924 and January 1925.  The fourth season was released on DVD and Blu-ray in region 1 on August 19, 2014.

Boardwalk Empire (episode): "Boardwalk Empire" is the pilot episode of the HBO crime drama "Boardwalk Empire".  Written by series creator Terence Winter and directed by Martin Scorsese with a budget of $18 million, the episode introduces the character of Nucky Thompson, played by Steve Buscemi, as the corrupt treasurer of Atlantic City who is involved in gambling and bootlegging in 1920.  The show used a large ensemble cast and a specially constructed boardwalk set to re-create the Prohibition and Jazz Era, and was based on "Boardwalk Empire: The Birth, High Times and Corruption of Atlantic City" by Nelson Johnson.  Filming for the pilot took place at various locations in and around New York City in June 2009.  The episode first aired in the United States on September 19, 2010.

Boardwalk Empire: Boardwalk Empire is an American period crime drama television series created by Terence Winter and broadcast on premium cable channel HBO.  The series is set in Atlantic City, New Jersey during the Prohibition era and stars Steve Buscemi as Nucky Thompson.  Winter, a Primetime Emmy Award-winning screenwriter and producer, created the show, inspired by the book "Boardwalk Empire: The Birth, High Times, and Corruption of Atlantic City" by Nelson Johnson about historical criminal kingpin Enoch L. Johnson.

Supporting paragraphs: Boardwalk Empire Enoch L. Johnson
Answer: 1941