Tony Cornero, a one-time 1920s bootlegger from California and a former casino operator well known in Las Vegas, opened the S.S. Rex Club casino at Second and Fremont streets in downtown Las Vegas in 1944. Cornero, born in Italy in 1895, named the club after an ill-fated gambling ship he owned off the coast of Southern California, six years before.

Back in 1931 in Las Vegas, Cornero and his two brothers built and ran the Meadows Club at Fremont Street and Boulder Highway, considered the first casino resort to debut in the town in the weeks after the Nevada Legislature legalized gambling. After a brief success, the business ran into trouble, and Cornero and his brothers lost control of the Meadows only months after it opened.

Cornero returned to California. In 1938, he operated the S.S. Rex gambling ship, about three miles off the coast of Santa Monica, in international waters where gambling was legal. But California prohibited gambling, and Cornero and his fellow cruise ship operators often ignored the three-mile limit. The state's attorney general, Earl Warren, deemed the boat illegal and the United States Coast Guard viewed it as a menace to navigation. Following a nationally publicized confrontation with the Coast Guard that lasted nine days at sea, Cornero was forced to close down his floating casino.

When Cornero returned to Las Vegas in 1944, he and partners rented the casino portion of the Apache Hotel and renamed it S. S. Rex for his infamous casino ship. The club became one of the small, neon-lit casinos, such as the Monte Carlo and Pioneer, which helped establish Fremont Street and Las Vegas as a national tourist attraction during and after the end of World War II. The S.S. Rex Club offered craps, poker, faro and other table games, plus a racehorse keno game with a $5,000 jackpot—quite large for the time—and a race book where bettors could place wagers on horse races that took place at two tracks in Mexico and one in Cuba.

But, like his other casino ventures in Las Vegas and California, Cornero's association with the S.S. Rex Club was controversial, and short-lived. In 1945, local police investigated charges Cornero's partners carried concealed guns and cheated at gaming tables there. After a dispute with his investors, Cornero was out of the S.S. Rex in 1946, and returned to California to run another offshore gambling ship that authorities soon closed. The S.S. Rex Club changed hands and in 1947, became the Eldorado Club.

Local casino investor Benny Binion bought the Eldorado, and the Apache Hotel, in 1951 and renamed it the Horseshoe Club. Cornero would later plan the ambitious Stardust Hotel project on the Las Vegas Strip, but he died in 1955—famously, while playing craps at the Desert Inn Hotel—three years before the Stardust opened.