In foreign policy, he was a moderate who took few initiatives. He unsuccessfully opposed the De Lesseps plan for building a Panama Canal, which he thought should be an American only program, Hayes asserted U.S. influence in Latin America and the continuing primacy of the Monroe Doctrine. Polls of historians and political scientists generally rank Hayes as an average president. In 1861, Congress had significantly raised tariffs with the passage of the Morrill Tariff, which funded the Civil War and also protected American industries like iron and steel.