Pennsylvania, one of the thirteen original states of the American Union, is situated between lat. 39° 43' and 42° 15' N., and between long. 74° 40' and 80° 36' W. The extreme length from E. to W. is about.300 miles, the extreme breadth 160 miles, and the area 45,215 square miles. It is bounded by New York on the N. and N.E., 'New Jersey on the E.', Ohio on the W., and West Virginia, Maryland, and Delaware on the S. The surface is varied, but falls into three main divisions : a level district in the S.E., extending onwards to the Atlantic; a mountainous region in the centre, which forms part of the Appalachian system, consisting of low parallel ranges running from N.E. to S.W. and separated by parallel valleys; and an upland plateau in the N. and W., from 1,000 to 2,500 feet above the sea, embracing one-half the area of the state. The mountainous region in the centre is in some places 100 miles broad. The principal rivers are the Delaware, which forms an irregular line along the E. border; the Susquehanna, which flows through the middle portion of the state from N. to S.; and the Ohio, which is formed in the W. by the union of the Alleghany and the Monongahela. The geological formation includes an Archaean region in the neighbourhood of Philadelphia, and Silurian and Devonian tracts, which extend into this state from that of New York, whilst W. of the Alleghanies conglomerate rocks predominate. There are two great coal districts, the bituminous beds lying in the W. part of the state, and the anthracites occupying the upland region between the Delaware and the Susquehanna. They are both sources of immense wealth, but the anthracite coal, which exists in Pennsylvania alone and is practically inexhaustible, is by far the more valuable. The annual output of anthracite coal is about 34.000.000 tons, that of bituminous about 25,000,000 tons. Natural gas is another important source of power. Near Pittsburg, the centre of the bituminous district, occurred the great Homestead strike (1892), the most serious labour disturbance that has ever taken place in the United States. Iron ore is found in abundance, and large quantities of pig-iron are produced. The obtaining of petroleum is also an important industry. The manufactures are numerous and varied, especially at Philadelphia. Agriculture is also in a. very thriving condition, a comparatively small portion of the soil being incapable of cultivation. The more elevated districts afford good pasturage, and dairy farming is carried on with great success. Owing to the vast quantities of timber, Pennsylvania occupies a leading position in the lumber trade, and the hemlock forests afford facilities for tanning. The original colony, established in 161, owed its existence to the energy of William Penn (q.v.). The state is divided into sixty-seven counties, and sends twenty-eight members to Congress. The mining population includes many Irish, Italians, and Hungarians. A considerable number of the tanners are descended from a German stock, and speak a language peculiar to themselves. Harrisburg is the capital, but Philadelphia (q.v.) and Pittsburg (q.v.) are the most important towns.