This study examines the causes of the countercyclicality of the trade balance in the three major sectors of the U.S. economy: services, manufacturing, and agriculture. These results are compared with the results pertinent to the U.S. economy as a whole. At the macroscopic level, Sachsâ€™ hypothesis seems to explain the countercyclicality of the trade balance, while results are mixed across individual sectors. The services sector may be explained by Sachsâ€™ hypothesis, while results for the manufacturing sector are more consistent with the real business cycle hypothesis. The results for the agricultural sector, however, cannot be explained by either hypothesis.