By 1940, gaming operations throughout the state were beginning to take hold. One of the most active areas in the 1940s was the emerging Las Vegas Strip. Many credit Benjamin “Bugsy” Siegel with creating the first Las Vegas Strip resort by developing the Fabulous Flamingo. However, five years earlier Thomas Hull opened the 57-acre El Rancho Las Vegas on San Francisco Street and the Los Angeles Highway in 1941. Today, these roads are known as Sahara Avenue and Las Vegas Boulevard.

R.E. Griffith and William Moore soon upstaged the El Rancho in 1942 with The Last Frontier, now known as The New Frontier.

The Flamingo was originally conceived by successful L.A. nightclub owner and publisher of The Hollywood Reporter, R.W. “Billy” Wilkerson. Due to reported debts, Wilkerson was forced to sell and it was Siegel who opened the Flamingo on December 26, 1946, and inherited the title as the man who “invented” Las Vegas. Even though it was not the first resort on the Las Vegas Strip, there is little debate that it helped raise the bar for what a Nevada hotel and casino could be.

1946 was a busy year in casino development with the opening of the famed Golden Nugget in Downtown Las Vegas; Harrah's Club, Nevada Club in Reno; the Wagon Wheel Casino and Tahoe-Biltmore Hotel-Casino near Lake Tahoe; The Mapes, in Reno, followed in 1947; and then The Thunderbird on the Las Vegas Strip in 1948.

Up until 1945, gaming licensing was handled at the local and county levels. Taxes were determined by the number of games or machines in operation. In that year, licensing authority shifted to the state level and Nevada enacted a new licensing program that, in addition to the per-game fee collected, enacted fees based on a percentage of gross-gaming win. The first Nevada state tax on gaming was levied in 1946 securing 1 percent of gross earnings, and revenue totaled $670,000 statewide.