of credit,
aided by a variety of other causes, prices have risen until their height
has become one of the most marked features and influential factors in
American life, producing social readjustments and contributing
effectively to party revolutions.

But if we avoid those statistics which require analysis because of the
changing standard of value, we still find that the decade occupies an
exceptional place in American history. More coal was mined in the United
States in the ten years after 1897 than in all the life of the nation
before that time.[313:1] Fifty years ago we mined less than fifteen
million long tons of coal. In 1907 we mined nearly 429,000,000. At the
present rate it is estimated that the supply of coal would be exhausted
at a date no farther in the future than the formation of the
constitution is in the past. Iron and coal are the measures of
industrial power. The nation has produced three times as much iron ore
in the past two decades as in all its previous history; the production
of the past ten years was more than double that of the prior decade.
Pig-iron production is admitted to be an excellent barometer of
manufacture and of transportation. Never until 1898 had this reached an
annual total of ten million long tons. But in the five years beginning
with 1904 it averaged over twice that. By 1907 the United States had
surpassed Great Britain, Germany, and France combined in the production
of pig-iron and steel together, and in the same decade a single great
corporation has established its domination over the iron mines and steel
manufacture of the United States. It is more than a mere accident that
the United States Steel Corporation with its stocks and bonds
aggregating $1,400,000,000 was organized at the beginning of the present
decade. The former wilderness about Lake Superior has, principally in
the past two decades, established its position as overwhelmingly the
preponderant source of iron ore, present and prospective, in the United
States--a treasury from which Pittsburgh has drawn wealth and extended
its unparalleled industrial empire in these years. The tremendous
energies thus liberated at this center of industrial power in the United
States revolutionized methods of manufacture in general, and in many
indirect ways profoundly influenced the life of the nation.

Railroad statistics also exhibit unprecedented development, the
formation of a new industrial society. The number of passengers carr