Contrary to popular perception organized crime in the person of Bugsy Siegel, a member of the Meyer Lansky crime organization did not introduce gambling to Las Vegas. Gambling had always been legal in Nevada until 1910 when a strict anti-gambling law was put into effect. Like prohibition this proved unenforceable in the rough and tumble state and legalized gambling was soon legal again. Divorce laws were also liberalized in the State of Nevada, making residency easier to attain. A "quickie" divorce can be attained after six weeks of residency. These short-term residents stayed at "dude ranches" which are the forerunners of the sprawling Strip hotels. In 1931 construction of Hoover Dam brought an influx of construction workers and Las Vegas grows to a population of 5,165.

In the 1940's Organized crime made their presence known to all that might have chosen to avert their eyes when Siegel was murdered by an unknown gunman who fired a shotgun blast as Siegel sat in the living room of the Beverly Hills, Calif., home of his girlfriend, Virginia Hill. Ironically Siegel had once famously noted of Syndicate members, "We only kill each other", Upon his murder Gus Greenbaum, Davey Berman, and Morris Rosen, three of the Syndicate's chief authorities, took over the Flamingo. The hotel's success prompted the Syndicate to pour more money into building Strip resorts, and by the 1950s, the Strip was lined with hotel-casinos, many, if not all, funded by Syndicate money. From the 1940s through the 1970s, Las Vegas and its lavish resorts were made possible in large part by the mob, who not only funded resort development, but offered indispensable knowledge in casino management. Men who had little-to-no criminal records fronted the resorts. Behind the scenes, so-called "Miami hotel men" took undeclared, thus untaxed, money from the establishment's profits. As the Syndicate's "chairman," Lansky was also the Syndicate's accountant. He was responsible for collecting, and then dividing, the skim. It's said that with increased law enforcement the role of organized crime in Les Vegas has diminished yet investigations have shown that organized crime including Russian and Israeli syndicates consider Las Vegas still to be wide-open territory.