A 1918 photograph preserved by the Library of Congress records horse-drawn wagons waiting their turn for coal in New York. Its caption says the line extended for six blocks. A shortage affecting heating and power became visible as vehicle length along a city street.
Unlike a modern petrol queue, the vehicles were wagons pulled by horses. Yet the underlying system is familiar: demand converged on a supply point and distribution proceeded by order of arrival. The photograph measures an energy shortage not in prices or tonnage, but in six blocks of occupied street.