““Once in public office, Mellon helped define the 1920s as an era during which business succeeded in rolling back many of the Progressive Era’s reforms. In 1921, capital gains taxes were cut, and the stock market boomed. After repeated efforts during his dozen-year tenure at Treasury, in 1926 Mellon finally succeeded in getting a bill passed that “cut the tax rates on the richest Americans more deeply than any other tax law in history,””