What does the telephone call from Chicago tell us about Gatsby's business?

In chapter 9, Nick Carraway is left in charge of managing Gatsby's estate and is forced to arrange his funeral. After Nick receives a brief and disappointing letter from Meyer Wolfshiem, Gatsby's phone rings and Nick answers the call. The phone call is from one of Gatsby's business associates, who is calling long distance from Chicago. The man's name is Slagle and he immediately tells Nick that "Young Parke’s in trouble" (Fitzgerald, 177). Slagle goes on to say that Young Parke was arrested after handing bonds over the counter and the authorities also caught him "giving ‘em the numbers" just five minutes before. When Nick responds by telling the man that Gatsby is dead, Slagle immediately hangs up. The long distance phone call and nature of the conversation suggest that Gatsby is involved in more crimes than illegally selling alcohol. Slagle's information confirms Tom's suspicion that Gatsby was involved in something much more criminal and serious than simply bootlegging. Overall, it confirms that Gatsby was deeply involved in the criminal underground and his business dealings were more sinister than previously expected.

In chapter 9, Nick answers a phone call for Gatsby that comes in from Chicago from a man named Slagle. The caller does not realize at first that he is talking to someone other than Gatsby, and he says to Nick,

Young Parke's in trouble . . . They picked him up when he handed the bonds over the counter. They got a circular from New York giving 'em the numbers just five minutes before.

When Nick eventually gets a word in, telling Slagle that Mr. Gatsby is, in fact, deceased, there is an exclamation followed by a lengthy silence, and then the line goes dead. This phone call makes it almost certain that Gatsby was involved in organized crime, which has been long associated with Chicago, and that he was not simply a bootlegger. No, now it becomes clear that he was involved in something much bigger, as Tom Buchanan had suggested during the confrontation in New York City several days earlier. We see that Gatsby's criminality was actually far more advanced than just selling illegal alcohol.