As a young man in Chicago, Rosenthal honed his skill as a sports better under the tutelage of the Chicago Outfit, which rose to prominence under Al Capone earlier in the twentieth century. After his arrival in Las Vegas, Rosenthal again went to work for the Chicago Outfit, this time secretly operating the Stardust, Hacienda, Fremont, and Marina casinos, which were controlled by the Mafia. He operated all of the casinos without a gaming license because the Nevada Gaming Commission, which suspected he had mob ties, refused to grant him one.
In addition to being a whiz with numbers, Rosenthal also proved himself a canny businessman. He brought sports betting, which had always been seen as a bit sleazy, to the Stardust, and created a plush, elegant environment where the practice flourished. He also brought in female blackjack dealers, a move which doubled the Stardust's income in the space of a year.
Rosenthal built a home for himself in the city's first guard-gated community in the Las Vegas Country Club. It was a high-tech home at the time; one room consisted only of monitors that allowed him to monitor the goings-on at the various casinos he ran. Reflecting the dubious circles in which he traveled, the home was built with bulletproof windows and doors. On once occasion, someone shot at Rosenthal from across the golf course. The bullet mark is still visible in the glass.
Rosenthal, whose life was the basis for the movie Casino, lived in the home just nine years. He built it in 1974 but moved to Florida in 1983 following an assassination attempt. The home was listed for sale as recently as August of 2017. It retains much of the Vegas-y feel that it had when Rosenthal called it home, including the bulletproof windows and doors.