Coolidge, Mellon, business organizations, and administration allies conducted a publicity campaign designed to convince wavering congressmen to support Mellon's tax plan. Their efforts were opposed by the coalition of Democrats and progressive Republicans that exercised effective control over the 68th Congress. In February 1924, the House Ways and Means Committee approved of a bill based on Mellon's plan, but an alliance of progressive Republicans and Democrats engineered passage of an alternative tax bill written by Democrat John Nance Garner; Garner's plan also reduced income taxes but set the top marginal tax rate at 46% rather than Mellon's preferred 33%. In June 1924, Coolidge signed the Revenue Act of 1924, which contained the income tax rates of Garner's bill and also increased the estate tax. Coolidge signed the bill but simultaneously called for further tax cuts. Congress also rejected Mellon's proposed constitutional amendment that would have barred the issuance of tax-exempt securities and, over Coolidge's veto, authorized a bonus to World War I veterans. Mellon did, however, win one legislative victory, as he convinced Congress to create the Board of Tax Appeals to adjudicate disputes between taxpayers and the government.