When gold and silver areincluded, there was only one year in the entire period in which theUnited States had an unfavourable balance of trade; and, as thecentury drew to a close, the excess of exports over importsincreased perceptibly. Agriculture continued to furnish the bulk of U.S. exports. Cotton,wheat, flour, and meat products were consistently the items with thegreatest annual value among exports. Of the nonagriculturalproducts sent abroad, petroleum was the most important, though bythe end of the century its position on the list of exports was beingchallenged by machinery. Despite the expansion of foreign trade, the U.S. merchant marinewas a major casualty of the period. While the aggregate tonnage ofall shipping flying the U.S. flag remained remarkably constant, thetonnage engaged in foreign trade declined sharply, dropping frommore than 2,400,000 tons on the eve of the Civil War to a low pointof only 726,000 tons in 1898. The decline began during the CivilWar when hundreds of ships were transferred to foreign registries toavoid destruction. Later, cost disadvantages in shipbuilding andrepair and the American policy of registering only American-builtships hindered growth until World War I.LabourThe expansion of industry was accompanied by increased tensionsbetween employers and workers and by the appearance, for thefirst time in the United States, of national labour unions. Formation of unionsThe first effective labour organization that was more than regional inmembership and influence was the Knights of Labor, organized in1869. The Knights believed in the unity of the interests of allproducing groups and sought to enlist in their ranks not only alllabourers but everyone who could be truly classified as a producer.They championed a variety of causes, many of them more politicalthan industrial, and they hoped to gain their ends through politics andeducation rather than through economic coercion. The hardships suffered by many wor...
