Stalin's death in 1953 and Nikita Khrushchev's rise to power lead to a slight ease in the tensions between the Soviet Union and the United States, known at the time as "the superpowers". ... And, unlike Stalin, he even visited the United States.
The answer here is that this meant that the US government was to stay out of the people's businesses and by large their affairs. This means that the transaction and deals between the parties happen without the interference of the government, there are no subsidies, no tariffs and no regulations on trade.
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It was the tariffs imposed by the Southern legislatures that hurt the economy in the South by taxing imported goods. The idea was to foster more good-creation domestically, but the US lacked the appropriate resources.