Mack was the owner of a supermarket in
Los Angeles, California in the 1920s. Mack was responsible for the establishment of the
Las Vegas Sun, the main newspaper in Las Vegas, when he loaned US$1,000 to its founder
Hank Greenspun in 1950. Mack co-founded the
Bank of Las Vegas with his son and other investors in 1954. Mack served as its chairman while
Walter E. Cosgriff was its president until he was succeeded by
E. Parry Thomas in 1961. The bank focused on loaning money to casinos in Las Vegas. Mack became "one of the most influential citizens of Las Vegas". ==Judaism==