The presidency of Calvin Coolidge began on August 2, 1923, when Calvin Coolidge became President of the United States upon the sudden death of Warren G. Harding, and ended on March 4, 1929. The Revenue Act of 1921, which had been proposed by Mellon, had reduced the top marginal tax rate from 71 percent to 58 percent, and Mellon sought to further reduce rates and abolish other taxes during Coolidge's presidency. With his legislative priorities in jeopardy following the debate over the Bonus Bill, Coolidge backed off on his goal of lowering the top tax rate down to 25 percent. In addition to cutting top rates, the tax acts also increased the amount of income exempt from taxation, and by 1928 only 2 percent of taxpayers paid any federal income tax. By 1930, one-third of federal revenue came from income taxes, one-third from corporate taxes, and most of the remaining third came from the tariff and excise taxes on tobacco.