The Blancs opened Le Grand Casino de Monte Carlo in 1858 and the casino benefited from the tourist traffic the newly built French railway system created.  Due to the combination of the casino and the railroads, Monaco finally recovered from the previous half-century of economic slump and the principality's success attracted other businesses. In the years following the casino's opening, Monaco founded its Oceanographic Museum and the Monte Carlo Opera House, 46 hotels were built and the number of jewelers operating in Monaco increased by nearly five-fold.  In an apparent effort to not overtax citizens, it was decreed that the Monégasque citizens were prohibited from entering the casino unless they were employees.  By 1869, the casino was making such a vast sum of money that the principality could afford to end tax collection from the Monegasques—a masterstroke that was to attract affluent residents from all over Europe in a policy that still exists today.