Like his father , Mellon consistently supported the Republican Party , and he frequently donated to state and local party leaders . Through state party boss Matthew Quay , Mellon influenced legislators to place high tariffs on aluminum products in the McKinley Tariff of 1890 . During the early 20th century , Mellon was dismayed by the rise of progressivism and the antitrust actions pursued by the presidential administrations of Theodore Roosevelt , William Howard Taft , and Woodrow Wilson . He especially opposed the Taft administration 's investigations into Alcoa , which in 1912 signed a consent decree rather than going to trial . In the aftermath of World War I , he provided financial support to Henry Cabot Lodge and other Republicans in their successful campaign to prevent ratification of the Treaty of Versailles . Mellon attended the 1920 Republican National Convention as a nominal supporter of Pennsylvania Governor William Cameron Sproul ( Mellon hoped Senator Philander Knox would win the nomination ) , but the convention chose Senator Warren G. Harding of Ohio as the party 's presidential nominee . Mellon strongly approved of the party 's conservative platform , and he served as a key fundraiser for Harding during the presidential campaign
1920 Republican National Convention
1920 Republican National Convention
Andrew Mellon