According to him, this aid could take the form of import duties or, in rare cases, prohibition of imports. He called for customs barriers to allow American industrial development and to help protect infant industries, including bounties (subsidies) derived in part from those tariffs. He also believed that duties on raw materials should be generally low "(Dorfman & Tugwell, Early American Policy, 1960)". Hamilton explained that despite an initial "increase of price" caused by regulations that control foreign competition, once a ""domestic manufacture has attained to perfection ... it invariably becomes cheaper"". The Congress passed a tariff act (1789), imposing a 5% flat rate tariff on all imports. "(Garraty & Carnes, 2000)" (Economics and World History: Myths and Paradoxes, Bairoch). Between 1792 and the war with Britain in 1812, the average tariff level remained around 12.5%. In 1812 all tariffs were doubled to an average of 25% in order to cope with the increase in public expenditure due to the war. A significant shift in policy occurred in 1816, when a new law was introduced to keep the tariff level close to the wartime level—especially protected were cotton, woolen, and iron goods "(The Age of Enterprise: A Social History of Industrial America, Thomas C. Cochran, William Miller, 1942), (Garraty & Carnes, 2000)". The American industrial interests that had blossomed because of the tariff lobbied to keep it, and had it raised to 35 percent in 1816. The public approved, and by 1820, America's average tariff was up to 40 percent. According to Michael Lind, protectionism was America's de facto policy from the passage of the Tariff of 1816 to World War II, "switching to free trade only in 1945". There was a brief episode of free trade from 1846, coinciding with the zenith of classical liberalism in Europe, during which American tariffs were lowered. But this was followed by a series of recessions and the panic of 1857, which eventually led to higher tariff demands than President James Buchanan, signed in 1861 (Morrill Tariff). In the 19th century, statesmen such as Senator Henry Clay continued Hamilton's themes within the Whig Party under the name "American System "(Abraham Lincoln and the Tariff, R. Luthin, 1944)"". The American Civil War (1861-1865) was fought over the issue of tariffs as well as slavery.