Coal
In 1939 the United States was the leading producer of coal in the world, supported by the fact that it lead the world in the use of underground mobile loaders for transportation of coal to the surface. Despite these two facts it was Great Britain which led in the area of full mechanization of mining, with the United States lagging behind by a significant margin. The US coal industry was hampered by government regulations and work stoppages led by the United Mine Workers. Alternative sources of fuel, such as natural gas or oil, were increasingly competitive. The US Navy had by the end of the 1930s converted all of its capital ships to burning oil rather than coal, and much of the shipping industry was following suit.
During the Great Depression, electrification of large areas of the country through the use of hydroelectric dams had reduced the need for coal. Many US cities had enacted regulations to ensure better quality air, reducing the use of coal as a heating fuel. The use of oil as a heating fuel was more efficient and more environmentally friendly, although that term had yet to enjoy frequent use. The coal industry also faced pricing established by government fiat, and profits were insufficient to adopt full mechanization necessary to compete.
When the United States entered the war one of the earliest measures taken was the rationing of oil and gas, with much oil being diverted to the war effort itself. The gap created by the removal of oil from the industrial and home heating market was filled by coal. Recognizing the need for steady and more efficient coal production the federal government worked with the industry to ensure coal producers received high priorities in the acquisition of new equipment and machinery. A stable work force was also required, and dispensations from the government helped achieve that goal. By 1943 coal production reached levels not seen in decades. Despite contentious strikes called during the war years, production continued to grow as the war went on, with 1944 being the largest in history.
It took the federal seizure of several mines to ensure that coal production continued at a record pace during the war. Labor leader John L. Lewis used the war and the need for coal as leverage in several work slowdowns and outright stoppages, causing the government to take over the mines. The government did so by forcing the mine owners to accept most of the union demands, thus punishing the owners for the actions of the workers, but continued production was the overriding concern.
By war’s end the United States produced over 2.1 billion tons of coal, more than its closest ally, Great Britain, but less than the 2.4 billion produced by Nazi Germany. Besides fueling much of the manufacturing industry in the United States and Canada, US coal provided heating for factories, schools, and homes throughout the country, freeing oil for use by the military. Coal was so critical to the US war effort that by 1943 deferments from the draft for coal miners as critical war industry workers were common.