Boardwalk Empire returns this Sunday, and as many of you likely know, the character at the center of Boardwalk Empire played by Steve Buscemi, Nucky Thompson, is loosely based on an actual person, Nucky Johnson, the political boss of Atlantic City throughout the Prohibition era. How similar are Nucky Johnson and Boardwalk’s Nucky Thompson?

The answer is: Similar, but not that similar. The author of the book that Boardwalk Empire is based upon, Nelson Johnson, said that Nucky Thompson is about 60 percent fact, and 40 percent fiction, although that was in the first season of Boardwalk Empire. The differences have increased significantly over three seasons. Now Thompson is really just a broad outline of what Johnson was, and any details revealed about Johnson are unlikely to be spoilers for Boardwalk Empire.

The differences begin with their physical appearances. Nucky Johnson was a huge man, tall, commanding, and boisterous, basically the opposite of the wan, sallow Steve Buscemi, who plays Nucky Thompson (nevertheless, Terence Winter had Buscemi in mind when he developed Boardwalk and built the cast around him). However, both Nucky Johnson and Nucky Thompson were very lavish, led very extravagant lives, and treated their friends very well. Nucky Johnson, like Thompson, provided his business associates with women, booze, and gambling, and even gifted their wives with furs. During the Prohibition era, Johnson also made $500,000 (or the equivalent of $5 million) a year, owned a powder blue limousine, and wore a $14,000 suit.

Similarly, Nucky Johnson took over political control of Atlantic City from Commodore Louis Kaestner, who Commodore Kaestner (Dabney Coleman) in Boardwalk Empire is based upon. Johnson took over when the Commodore went to prison for corruption in 1912, and when he returned in 1920, the Commodore attempted to seize back control of Atlantic City, although it was nothing like depicted in Boardwalk Empire. There was no violence involved, and in fact, after the Commodore failed to regain control, Nucky Johnson supported him as City Commissioner, a position the Commodore held until his death in 1934 (there was no violence or a brothel owner behind his death).

As for Nucky Thompson’s brother, who Nucky installed as sheriff in Boardwalk Empire, in actuality, Nucky Johnson began his own political career as the undersheriff, taking over for his father, who had served as both sheriff and undersheriff for years (no one was allowed to consecutive terms as sheriff, so Nucky Johnson’s father simply alternated positions, until he installed his own son as undersheriff).

In the broadest sense, however, Nucky Thompson is like Nucky Johnson during Prohibition. He had complete control over Atlantic City. He lived on an entire floor of the Ritz. He maintained that power mostly through kickbacks, bribery, favors and corruption. There was no doubt that Nucky Johnson was ruthless and immoral, but there wasn’t really any physical violence involved, as there obviously is in Boardwalk. Nucky Johnson operated through fear: If he didn’t get what he wanted, he would take a person’s job or position of power away. Nucky Johnson wasn’t involved in turf wars over liquor, either. He basically took a percentage of every gallon of booze that entered the city, as well as a percentage on all the prostitution and gambling operations in the Atlantic City. He didn’t have a lot of folks challenging him for authority.

Was he business associates with Arnold Rothstein, Lucky Luciano, Meyer Lansky, and Al Capone? Why, yes, actually, although the timeline is off. The “Combined” or the “Big Seven Group” — a loose organization of bootleggers and racketeers that included Rothstein and Johnson — wasn’t formed until 1927 (the action in season three of Boardwalk Empire began in 1922). Al Capone was not a part of the Big Seven due to a rivalry. The Big Seven was actually the predecessor organization to The National Crime Syndicate (and Murder, Inc.), which did include Capone, as well as big names like Luciano, Lansky, Benjamin “Bugsy” Siegel, and Frank Costello. However, even before 1927, Johnson had loose associations with many of those figures, though he was not directly involved in gang wars.