The turn of the century brought a series of changes to Bethlehem, mostly through the growth of its steel industry. The changes are greatly accredited to one man, Charles M. Schwab. He brought to this small town many of the large-scale business practices he has learned at U.S. Steel from Andrew Carnagie. These included a sharp distinction between management and labor, which occurred both inside and outside the workplace. He also instituted the revolutionary "bonus system," which rewarded high production levels on a individual basis. This system and modest wages continued to attract immigrants to Bethlehem to work in the steel mills. Under Schwab, and with the help of WWI, Bethlehem Steel increased in size and production. This in turn caused the population and financial backing of Bethlehem to skyrocket, and brought about the mentality of Bethlehem as a prosperous "steel town."