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 contributed more than 2,000,000,000 feet a year after 1890, and the shipments of lumber and shingles from this region to the interior were beginning to take on very large proportions.