Oh boy, finally something I can say I'm good at talking about. The mafia declined for several reasons, which really began to kick off during the 1950s. Yes, Capone and his crew were all the rage about two to three decades beforehand, but the American Mafia still held immense power even with his demise. It should be known that the mafia was originally a secret society and was purposely kept in the shadows for years.

In 1951 however, the Senate held a committee called the Kefauver Hearings which questioned several suspected capos (captains) and bosses in the Mafia. Very few of them revealed much useful information.

Police got wind of a Mafia Commission (a kind of board of directors for the Mafia, where bosses across the country meet) meeting in Apalachin, NY in 1957 and raided the meeting, confirming the existence of a nationwide organized crime syndicate. Everyone in law enforcement, even J. Edgar Hoover, was forced to admit that this syndicate was now a problem.

The REAL downfall began when the RICO Act was passed in 1970, allowing law enforcement to charge an entire organization with racketeering charges. This led to a huge amount of high-ranking Mafiosi being thrown in prison, and also led to many others becoming informants because of the stuff punishments that came with a RICO charge. From the 1980s to the 1990s, the mafia lost more and more power, which reached a peak once in the early 90s when John Gotti was at the peak of his power and soon lost it in 1992. This was a clear example that flashy, high-profile Mafiosi could not effectively operate in modern society, as they attracted far too much law enforcement attention. In the early 2000s, the mob took another hit when Joe Massino, the Bonnano Family boss, turned state's witness, which was unheard of for a boss.

Keep in mind that the mafia has slowly been coming back behind the scenes. As US law enforcement focuses more on national security (NSA and terrorism) and less on organized crime, the mafia has reclaimed some of their old business, and remains the largest (and most profitable) organized crime group in the US despite the Russian Mafia and Chinese Triads gaining some of their own clout.