Since no one has answered in 24 hours:
Al Capone (his sister's name was Mafalda).
Q. Which former Don's daughter is a published author?

John Gotti's daughter is an author I believe.

Also didn't Toni Giancana publish a book as well? I think you meant Gotti.

Either way in case I'm correct.

Q. What gangster was killed by his girlfriends daughter?

Johnny Stompanato, by Cheryl Crane, Lana Turner's daughter.
Q. Which gangster's son graduated from West Point?

I'm not sure but wasn't it Meyer Lansky?

Meyer Lansky is correct. Your turn, Juventus:

Juventus seems to have disappeared.
Q. Which Prohibition-era beer baron's real name was Arthur Flegenheimer?

Dutch Schultz
Q. nicknamed "Big Pauly".

GoodFella

Paul Castellano.
Q. Which Gambino capo owned a restaurant, "Cafe Biondo," in NY's Little Italy?

Joseph "Joe Butch" Corrao(if this is right . . .)
Q. Ace Rothstein's(Casino) name in real life.

GoodFella

A: Frank "lefty" Rosenthal

Q: Nicky Santoros character is based off what real gangster?

Tony the Ant Spilotro.
Who hung himself in his basement in 1959?

Abner (Longie) Zwillman.
Q. Whose hands (and only his hands) were televised during the Keefauver hearings in 1951?

A. Frank Costello

Q. He controlled the Teamster's Central States Pension Fund and was gunned down in a hotel parking lot in suburban Chicago in 1975.

tony b.

Alan Dorfman.
Q. This New York union president was a brother of a Mafia Don, but spelled his last name differently.

A. Albert Anastasia and his brother Tony Anastasio.

If that's correct...here's an easy one...

Q. Even the Laborer's International Union acknowledges that organized crime has infiltrated its locals, particularly the local that represents the City of Chicago Streets and Sanitation workers. And that would be Local (number please...)

tony b.

1001.
Q. This movie industry labor racketeer was blown up in a car bombing in 1955.

A. Willie Bioff.

Q. Let's stick with the unions ("Now we have the unions, we have the gambling; an' they're the best things to have."). He ruled the Laborer's Union in Chicago for nearly an entire generation, dodging at least two attempts on his life. It's as if he walked around with a big "X" on his back!

tony b.

A. Joe Lombardo.
Let's move it beyond Chicago:
Q. (easy one): What was Joe Adonis' real name?

A: Guiseppe Doto

Q: It was alleged that this famous gangster ratted some friends out when he was a teenager

I'm thinking Lucky, but I'm not 100% sure.

your correct! post a question

Turnbull...Joe Lombardo was the incorrect name. The correct answer is Frank "Frankie The X" Esposito.

"...and the countdown rolls on."

tony b.

YoTonyB- Is that a question?
If Not- What was Lansky's real last name, and where was he born?

Maier Suchowljansky from Grodno, Russia.
Q. Who was mentor to Lansky, Charlie Luciano and Frank Costello?

A. Arnold Rothstein

Q. this is a 2 parter.

Part 1-This gal was referred to as the "Blonde Alibi" Why was that?

Part 2-What was her name?

Louise Rolfe was "the blond alibi." She was Machine Gun Jack McGurn's mistress, and she and McGurn holed up in a Chicago hotel during the St. Valentine's Day Massacre in order to establish that McGurn wasn't present at the shooting.
Q. Who was the only man that Capone killed with his own hands after he left Brooklyn? (Hint: it wasn't Scalisi, Anselmi or Giunta, who were still breathing after he baseball-batted them and were dispatched by his bodyguards.)

I'm back..I couldn't get on the net cause my pc didn't work...
But TB i'm not sure but i think the answer is Big Jim Colosimo...Some people say Frankie Yale killed him others say it was Al Capone..
But i'm not sure.....

Welcome back!
Good guess, Juventus, but most people now think Yale, not Capone, killed Colosimo. Laurence Bergreen Capone's most recent biographer, believes Capone wasn't even in Chicago at the time of Colosimo's murder.
Question still stands:
Q. Who was the only man that Capone killed with his own hands after he left Brooklyn? (Hint: it wasn't Scalisi, Anselmi or Giunta, who were still breathing after he baseball-batted them and were dispatched by his bodyguards.)

Since no one has answered:
The guy Capone killed was Joe Howard, a local gangster who slapped around Jake (Greasy Thumb) Guzik, Capone's close pal, and then insulted Capone when he confronted Howard.
Q. (Timely one): Which Don was known for his Fourth of July fireworks displays?

John Gotti?

If so...

Q: what outside boss wanted gotti dead?