d Tennessee field. It provided fuel for the growing
manufacturing industries of the south-eastern portion of the country
and competed for the coal trade of points on the lower Mississippi.

_Iron Ore, Iron and Steel._ The development of the movement of iron ore
from the mines around Lake Superior to the furnaces of the Eastern
States was one of the most interesting features of the internal trade
of the United States during this entire period. This trade grew in
volume from less than 1,000,000 tons in 1870 to 18,000,000 tons in
1899, the shipments during the latter year comprising two-thirds of the
total iron ore production of the whole country. Practically the entire
traffic went by lake vessels to ports on Lake Erie and Lake Michigan
whence it was taken by rail to the blast furnaces of Pennsylvania,
Ohio, New York and Illinois.

No other industry in the United States had a more remarkable growth
after 1860 than the iron and steel industry. The production of pig iron
in 1899 was nearly 15,000,000 tons, and of crude steel almost
11,000,000 tons. Pennsylvania contributed about one-half of the entire
output of both pig iron and steel during the forty years, Ohio ranking
second. The pig iron industry began to expand rapidly in Alabama and
Illinois in the early eighties, and by 1900 the output of these two
states constituted a fifth of the total product. The immense output of
iron and steel was distributed everywhere throughout the country. A
large part of it was used in building the railroads and the remainder
was utilized as the raw material for the manufacture of a great variety
of iron and steel products that were used in all branches of industry.

_Lumber._ The forests of the United States were subjected to a rapid
and often wasteful exploitation during these years. Extensive building
operations, the construction and maintenance of an enormous railway
mileage and the growth of manufacturing created a heavy demand for
timber, and by 1900 the annual cut amounted to 35,000,000,000 feet. The
northeastern group of states which had formed the chief source of
lumber supply before 1860, lost precedence by 1880 to the lake states,
Michigan, Wisconsin and Minnesota. The tremendous consumption of timber
throughout the country rapidly depleted the supply in this district and
by 1900 the yellow pine of the South was being heavily drawn upon,
forming a fourth of the production of the country. The timber lands of
the Pacific coast c