Prior to the 1850s there had been only a very gradual expansion of the coal industry and on the eve of the Reciprocity Treaty of 1854 production had reached about 150,000 tons (135,000 metric tons) per annum. After a smooth transition to the St. Lawrence market, expansion was interrupted by the economic slump of the 1870s, but this was followed by another long-term, upward trend which accelerated just prior to World War I. The post-Confederation stimuli which carried the industry were the growth of the central Canadian market and the enormous capacity of the steel mills built at the turn-of-the-century in Cape Breton; the United States market proved a constantly declining factor. Production after the war reflects the conscious policy of the federal government to support the activities of the Nova Scotia coal industry to only a certain level. Freight subventions and guarantees to the St. Lawrence market were reviewed in the post-World War II period as the use of other forms of energy was expanded to replace coal in central Canada. The major oil discoveries of the 1940s in Alberta contributed a great deal to the final decline in coal production and cutbacks in the 1950s.
