The series timeline includes events in the nineteenth and twentieth centuries.
Nineteenth century
- 1814: The first constitution of Norway is signed on May 17, proclaiming Norway a state independent of Denmark.
- 1831: The Fitzgerald Distillery is established. ("Battle of the Century")
- 1839: Ethan Thompson is born. ("Battle of the Century")
- 1843: Louis Kaestner is born ("Paris Green")
- 1845-1852: Great Famine in Ireland.
- 1848: Elenore Thompson is born. ("Battle of the Century")
- 1861: The American Civil War begins.
- 1863: The Battle of Vicksburg takes place. The Commodore's brother is killed during the battle. ("Paris Green")
- 1865: The American Civil War ends.
- 1867: Jackson Parkhurst takes part in the Wagon Box Fight during Red Cloud's War. ("Gimcrack & Bunkum")
- 1868: Eddie Kessler is born in Germany
- 1871: Great Chicago Fire
- 1876: Custer's Last Stand at the Battle of Little Bighorn
- 1881: Nucky Thompson is a member of the Atlantic City Junior Beach Patrol. ("Home")
- 1883: Damien Fleming is born ("Ourselves Alone")
- 1884: Gillian Darmody is born on June 15. ("Marriage and Hunting")
- 1885:
- Mabel Thompson is born. ("A Return to Normalcy")
- Harry Daugherty and Jess Smith hide in Daugherty's parents' house as a tornado swepts Washington Court House, Ohio. The victims include 10-year old Mary Shakledorf. ("A Man, A Plan...")
- 1888:
- A great winter blizzard falls over Atlantic City. ("Boardwalk Empire")
- Nucky Thompson claims to have searched for food chest deep in snow in order to feed his family, ultimately killing three rats, while his father Ethan Thompson was drunk. He later denied the story, however. ("Boardwalk Empire")
- Mickey Doyle is born
- 1892: Doomsday cult leader Edgartin Sterry prophesies the Second Coming to take place in this year. Nelson Van Alden's father, one of his followers, gives away the family farm in anticipation and the family awaits in a tent for the whole of the year. Van Alden's relation with his parents begins to sour afterwards.
- 1893: Margaret Schroeder is born. ("Family Limitation")
- 1894: Nelson Van Alden's aunt takes him to a play, his fundamentalist parents are enraged and shun all contact with her. ("A Dangerous Maid")
- 1897: Gillian is raped by The Commodore on May 1. Nucky set up their meeting. ("Paris Green")
- 1898:
- Jimmy Darmody is born in January.
- Chalky White runs dice at the beach and meets Nucky for the first time. ("The Emerald City")
- Julia Sagorsky is born. ("A Man, A Plan...")
- Valentin Narcisse leaves his native Trinidad and enters the United States through New Orleans. ("Farewell Daddy Blues")
- Spanish-American War
- 1899: Beginning of the Philippine-American War
Twentieth century
1900s
- 1900: Paul Sagorsky fights at the Siege of Catubig in the Philippines.
- 1901:
- Booker T. Washington makes a stop in Atlantic City.
- Chalky claims that he met The Commodore for the first time and found out that Nucky had been overtaxing him for 3 years. ("The Emerald City")
- 1902: Official end of the Philippine-American War (fighting in the south continues until 1913)
- 1903:
- Elenore Thompson dies aged 55. ("Battle of the Century")
- Manny Horvitz and his wife move to the United States. ("Resolution")
- 1904: Rowland Smith is born
- 1905: Gillian tries to marry Mr. Lancaster ("Anastasia")
- 1907: Gyp Rosetti's first daughter is born. ("Margate Sands")
- 1908:
- Nelson and Rose Van Alden are married. ("21")
- Jimmy, The Commodore and Nucky attend a speech by Republican Presidential nominee William Howard Taft. ("The Ivory Tower")
- 1909:
- Margaret gets pregnant with Douglas Walton's child, the son of the barrister she was working for as a maid. Refusing to tell the father's identity, and threatened with being confined to a Magdalene Sisters asylum, she steals Eamonn Rohan's passage and immigrates to the United States. She miscarries on arrival. ("Family Limitation")
- Hans Schroeder becomes baker's helper ("The Ivory Tower").
- A workers strike in Atlantic City is put down violently ("Georgia Peaches")
- Gyp Rosetti's second daughter is born. ("Margate Sands")
1910s
- 1910:
- Jimmy begins to work for Nucky at age 12. ("Boardwalk Empire")
- Fred Sagorsky wins a school championship in athletics. ("Sunday Best")
- 1911: Esther Randolph becomes a public defender in California ("Peg of Old")
- 1912:
- Nucky (then Atlantic County Sheriff) arrests Hans Schroeder for public indecency during Oktoberfest. ("The Ivory Tower").
- The Commodore Louis Kaestner is charged and imprisoned for election rigging during a PR campaign by then Governor Woodrow Wilson. Nucky succeeds The Commodore as new Atlantic County Treasurer ("Boardwalk Empire", "A Return to Normalcy")
- Enoch Thompson Jr. is born and dies in the second half of December. ("A Return to Normalcy")
- 1913:
- Mabel Thompson commits suicide aged 28. ("Boardwalk Empire", "A Return to Normalcy")
- Manny Horvitz begins working with Waxey Gordon. Their relationship goes awry by 1921. ("What Does the Bee Do?")
- Victor Sickles contacts Eli Thompson, interested in joining some police force in New Jersey. ("Spaghetti and Coffee")
- Eddie Kessler begins to work for Nucky Thompson. ("Resignation")
- 1914:
- Teddy Schroeder is born in March. ("Acres of Diamonds")
- The Commodore makes his last and only will, leaving everything to Louanne Pratt ("To the Lost")
- World War I begins.
- Rowland Smith's family receives a Christmas turkey from Nucky Thompson. ("Blue Bell Boy")
- Paul Sagorsky starts drinking ("The North Star")
- 1915:
- Adeline White is born. ("Havre de Grace")
- Chalky White sees Oscar Boneau for the last time before 1924. ("Havre de Grace")
- The RMS Lusitania is torpedoed by a German submarine, sparking anti-German protests in the United States.
- 1916:
- Emily Schroeder is born in May. ("The Milkmaid's Lot")
- Gillian dates Arthur Henderson until he dumps her ("Under God's Power She Flourishes")
- Jimmy and Angela meet in Princeton and begin a relationship. She gets pregnant with Tommy late in the year ("Under God's Power She Flourishes")
- Gillian visits Jimmy at Princeton. During her stay she sleeps with her son and causes him to get in a fight with his teacher Mr. Pearson, guaranteeing Jimmy's expulsion from the College. ("Under God's Power She Flourishes")
- Jimmy enlists in the US Army. ("Under God's Power She Flourishes")
- Last photos of Richard Harrow with Emma and the rest of his family in Plover, Wisconsin. ("Ging Gang Goolie")
- Easter Rising against British occupation in Ireland.
- 1917:
- Tommy Darmody is born. ("Under God's Power She Flourishes")
- The Rohann family move to the USA. ("A Dangerous Maid")
- The D'Alessio brothers rob a restaurant and kill 3 people. ("Belle Femme")
- The United States of America declare war on Germany.
- Jimmy receives instruction at Camp Grant, Illinois before leaving to fight in World War I. ("Boardwalk Empire"). Richard Harrow presumably does the same.
- Nucky ends his relationship with Annabelle and begins seeing Lucy Danziger. ("Home")
- The Commodore gets out of jail ("A Return to Normalcy")
- Margaret stops attending confession regularly. ("The Age of Reason")
- Russian Revolution and beginning of the Russian Civil War.
- 1918:
- Angela meets Robert and Mary Dittrich. ("Belle Femme")
- Jimmy earns a medal for his role in the Battle of Saint-Mihiel ("Boardwalk Empire")
- Jimmy is injured by a German grenade during the Meuse-Argonne Offensive and is treated in a field hospital in Verdun. Experimental surgery is able to save his leg. Fred Sagorsky is killed during the same battle. ("Anastasia", "Home", "Ging Gang Goolie")
- Julia Sagorsky considers marrying Douglas. ("A Man, A Plan...")
- World War I ends.
- Nicholas II of Russia and his family are executed by the Bolsheviks.
- 1919:
- The Irish War of Independence begins.
- Jimmy spends several months at the Walter Reed Hospital in Washington DC and returns to Atlantic City in January of next year. ("Home", "Broadway Limited")
- Arnold Rothstein fixes the World Series, resulting in the Black Sox Scandal.
- A drunken member of the Order of Ancient Celts throws a midget known as "Captain Haddock" over the Boardwalk. ("Nights in Ballygran")
- The League of Nations is formed.
- The 18th Amendment to the US Constitution is ratified.
- August Tucker leaves Georgia for Tampa, Florida. ("Acres of Diamonds")
1920s
1920
- 1920: First season
- January - "Boardwalk Empire", "The Ivory Tower", "Broadway Limited"
- February - "Anastasia"
- March - "Nights in Ballygran"
- April - "Family Limitation"
- May - "Home"
- June - "Hold Me in Paradise"
- July - "Belle Femme"
- August - "The Emerald City"
- September - "Paris Green
- 14: Sacco and Vanzetti are indicted for armed robbery.
- 16: Wall Street Bombing.
- October 31 to November 2 - "A Return to Normalcy"
- December 11-12: British paramilitaries set fire to several buildings in the Irish city of Cork and shoot at the firemen when they try to contain the flames.
- Undated: Owen Sleater plants his first bomb at some Black and Tans barracks in County Tipperary, Ireland. ("What Does the Bee Do?")
- Undated: Bill McCoy meets August Tucker in Florida for the first time. ("Acres of Diamonds")
1921
- 1921: Second season
- February - "21", "Ourselves Alone"
- March - "A Dangerous Maid"
- April - "What Does the Bee Do?"
- May - "Gimcrack & Bunkum"
- June - "The Age of Reason", "Peg of Old", "Two Boats and a Lifeguard"
- July:
- 1 to 2 - "Battle of the Century"
- 23 to 25 - "Georgia Peaches"
- 26 to 27 - "Under God's Power She Flourishes"
- August - "To the Lost"
- December - The Anglo-Irish Treaty is signed, proclaiming the Irish Free State as a dominion under British sovereignty.
1922
- 1922:
- Undated: Arnold Rothstein introduces Nucky to Gyp Rosetti. ("You'd Be Surprised")
- October - End of the Russian Civil War.
- November - Howard Carter discovers King Tutankhamun's tomb.
- December:
- 12: Nucky Thompson is awarded the title of Knight Commander of the Papal Order of Saint Gregory the Great. The ceremony of acceptance is set to take place on January 9, 1923. ("Spaghetti and Coffee")
- "Some time before" 25: George Mueller sells a defective iron to Prohibition Agent Emmett Coughlin.
- 31: "Resolution"
1923
- 1923: Third Season
- Undated - Owney Madden opens the Cotton Club in New York City
- January - "Resolution", "Spaghetti and Coffee", "Bone for Tuna", "Blue Bell Boy"
- Edward Edwards finishes his term as Governor of the state of New Jersey
- February - "You'd Be Surprised"
- March - "Ging Gang Goolie"
- April - "Sunday Best"
- Richard and Emma Harrow's father dies, making them orphans ("Resignation")
- May - "The Pony", "The Milkmaid's Lot"
- Emma Harrow marries Gerald ("Resignation")
- June:
- 21 - "A Man, A Plan..."
- 22 - "Two Imposters"
- 26 to 27 - "Margate Sands"
- July-August - Tommy Darmody talks again after a month speechlessness as a result of the massacre at The Artemis Club. ("New York Sour")
- August:
- Emma Harrow becomes pregnant ("Resignation")
- Warren G. Harding dies of a heart attack
- Calvin Coolidge becomes the 30th President of The United States
- October - Bill Lovett is killed in Brooklyn. Peg Leg Lonergan takes over his business and begins a two year war against Frankie Yale for control of the Brooklyn Waterfront.
- November - Gerald dies, making Emma a widow ("Resignation")
1924
- 1924: Fourth Season
- January:
- While in jail, George Remus tells the Bureau of Investigation that Nucky Thompson is 'the linchpin of a nationwide criminal conspiracy'. ("William Wilson")
- BoI Agent James Tolliver travels to Atlantic City and poses as BIR Agent Warren Knox to investigate Nucky's organization and the corruption within the Prohibition Agents deployed there. ("New York Sour", "Resignation")
- February - "New York Sour", "Resignation"
- 3: Woodrow Wilson dies
- March - "Acres of Diamonds", "All In"
- April - "Erlkonig", "The North Star"
- Harry Daugherty is forced to resign his post as Attorney General by the late Harding's Presidential successor, Calvin Coolidge
- May:
- 21 to 22 - "William Wilson"
- 23 to 24 - "The Old Ship of Zion"
- June - "Marriage and Hunting"
- July - "White Horse Pike", "Havre de Grace"
- August - "Farewell Daddy Blues"
- January:
1925:
- 1925:
- Undated:
- George Remus is indicted for thousands of violations of the Volstead Act and given a two-year federal prison sentence
- Johnny Torrio moves to Italy
- March: Calvin Coolidge begins his second term as the 30th President of The United States
- December: Peg Leg Lonergan and five of his men are killed at the Adonis Social Club during a Christmas celebration
- Undated:
1926:
- 1926:
- Undated:
- Al Capone is at the climax of his power
- Gaston Means is released from federal prison after serving two years
- September:
- Twelve cars full of gangsters open fire at The Hawthorne Inn, Al Capone's Chicago headquarters. Only one of Capone's men is wounded
- Jack Dempsey looses his Title against Gene Tunney in Philadelphia
- October:
- Harry Houdini dies of gangrene
- Hymie Weiss, successor to Dean O'Banion, is killed outside the former O'Banion flower shop North Side headquarters
- Undated:
1927:
- 1927:
- Undated:
- The Combined criminal organization is formed, Lucky Luciano and Meyer Lansky are major supporters. It's original members include; Nucky Thompson, Waxey Gordon, Benny Siegel, semi-retired Johnny Torrio and many other criminal associates. Al Capone expressed interest in joining, however his war with the North Side Gang prevented him from doing so. Joe Masseria and Salvatore Maranzano were not members.
- Frankie Yale and Al Capone's long friendship begins to sour. Yale had been hijacking Capone's alcohol.
- Salvatore Maranzano is sent with several other men from Sicily to gain control of the American Mafia
- January: Mayor Edward Bader dies of appendicitis
- April: Bill Fallon dies of natural causes
- September: Al Capone invites Frankie Yale to Chicago to mend their relationship. Despite the visit going well, their friendship began to rapidly deteriorate after Yale returned to New York. Due to many other business obligations, Capone would have to wait until 1928 to retaliate.
- October: George Remus goes on trial for the murder of his ex-wife, Imogene. Remus pleaded temporary insanity and was granted a six-month insanity sentence. Upon release, Remus attempted to get back into bootlegging, but soon retired when he found that the market had been completely taken over by gangsters.
- Undated:
1928:
- 1928:
- Undated:
- Johnny Torrio returns to the United States as Benito Mussolini begins putting pressure on the Mafia in Italy
- Waxey Gordon's position begins to decline following Rothstein's assassination
- Eliot Ness begins to lead the Prohibition unit in Chicago
- Tensions between the Masseria and Maranzano factions increase
- July:
- Frankie Yale is murdered by four armed individuals in Brooklyn, New York
- Following the death of Frankie Yale, Joe Masseria begins to take entire control of all the Mafia gangs of New York
- November: Arnold Rothstein is shot and mortally wounded during a business meeting in Manhattan, he died the next day. The shooting was reportedly linked to debts owed from a three-day long, high stakes porker game a month earlier. The gambler George "Hump" McManus was arrested for the murder, but later acquitted for lack of evidence. Following this, Lucky Luciano quickly pledges fealty to Joe Masseria
- Undated:
1929:
- 1929:
- Undated: Joe Masseria is now formally known as "Joe the Boss," head of the largest Mafia grouping in New York. Lucky Luciano, now a top aide in the Masseria organization, reluctantly begins paying homage and tribute.
- January: Benny Siegel marries Esta Krakower
- February: The Saint Valentine's Day Massacre occurs, seven mob associates of the North Side Irish gang led by Bugs Moran, successor to Hymie Weiss, are killed.
- March:
- Herbert Hoover is elected the 31st President of The United States
- Following the election of President Herbert Hoover, U.S. Treasury Secretary Andrew Mellon was specifically charged with bringing down Al Capone. Eliot Ness was chosen to head the operations under the National Prohibition Act targeting the illegal breweries and supply routes of Capone. Ness creates a team of nine men known as "The Untouchables" to help in his effort.
- May:
- The Atlantic City Conference occurs. It was a major summit held in Atlantic City of leaders of organized crime in the United States and was the earliest organized crime summit in the U.S. Many details were discussed, most notably the violent bootleg wars in New York and Chicago, investment into legal ventures in case of the repeal of prohibition and reorganization and consolidation of the underworld into a National Crime Syndicate. The Conference was hosted by Meyer Lansky, Lucky Luciano and Johnny Torrio, the organizing host was Nucky Thompson who provided all the arrangements. Some of the attendees include; Benny Siegel, Owney Madden, Al Capone, Jake Guzik, Waxey Gordon and many more. Joe Masseria and Salvatore Maranzano were excluded once again and not invited.
- Meyer Lansky marries Ana Citron
- October:
- Lucky Luciano is forced into a limousine at gun point by three men, beaten and stabbed, and dumped on a beach in Staten Island.He survived the ordeal but was forever marked with a scar and droopy eye.
- The Wall Street Stock Market Crash of 1929 occurs, beginning the ten-year long Great Depression
- November:
- Senator Walter Edge resigns from his post as a Senator of New Jersey to become the U.S. ambassador to France
- The efforts of Eliot Ness and his team bring major damage to Capone and his organization
1930s
1930:
- 1930:
- Undated:
- A "Jake paralysis" outbreak occurs in the United States resulting from adulterated Jamaica ginger sold as an alcohol substitute
- Bugs Moran flees Chicago
- The Chicago Crime Commission designates Al Capone Public Enemy No. 1
- At this time, Al Capone has fully consolidated his power in Chicago and is effectively in full control. He is a force to be reckoned with.
- January: Harry Bacharach is once again elected as Mayor of Atlantic City
- February: Joe Masseria issues a decree ordering the death of Salvatore Maranzano, in return Maranzano declares war on Masseria. These events mark the formal beginning of the Castellammarese War, the bloodiest and most important Mafia war in history.
- November: As 1931 approaches, the tide begins to turn and the war starts going poorly for Masseria. Lucky Luciano, his trusted friends and associates seek to secure their positions in the coming power struggle.
- Undated:
1931
- 1931: Fifth Season