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During the 19^th century, the United States generally had a negative trade balance, importing more than it exported, particularly from the British Empire. This changed at the turn of the 20^th century, and the U.S. consistently had a positive trade balance between 1896 and 1970. The greatest periods of fluctuation came during the world wars, as well as an observable decline following the Wall Street Crash of 1929.

While inflation rates increased the total value of imports and exports over time, the rate of growth did increase significantly from 1900 onwards. The early 20^th century saw the U.S. move away from its traditional isolationist policies (apart from a brief period during the great Depression) and emerge as a global superpower. Following the Second World War, the U.S. used its economic power to maintain its influence across the globe, as it sought to suppress the expansion of communism.