Protectionism in the United States is protectionist economic policy that erected tariff and other barriers to trade with other nations. This policy was most prevalent in the 19th century. It attempted to restrain imports to protect Northern industries. It was opposed by Southern states that wanted free trade to expand cotton and other agricultural exports. Protectionist measures included tariffs and quotas on imported goods, along with subsidies and other means, to ensure fair competition between imported goods and local goods.