Pennsylvania, since 1830 the second in population of the United States, is a parallelogram lying between New York and Maryland, Ohio and New Jersey. The Delaware is the boundary on the E.; and in the NW. the state has 45 miles of coast on Lake Erie. It is 160 miles wide and 302 long (E. to W.); in area (45,215 sq. m.) it is the twenty-ninth state of the Union. The Appalachians (q.v.) cross the state from NE. to SW.; between the Blue or Kittatinny Mountains on the east and the higher Alleghany range (some peaks 2500 feet) on the west lie numerous minor forest-clad chains. The surface is naturally divided into three sections, the low district southeast of the mountains containing some of the best farming land; the mountainous region embracing a fourth of the area of the state, and celebrated for its picturesque scenery (especially for the gaps cut by the rivers through the ranges of hills); and the broken hilly plateau in the west, covering half the state, much of it heavily wooded. The geology is remarkable for the great development of the different periods of Palaeozoic. The breaking of the strata and the enormous pressure to which the eastern coal-deposits have been subjected has resulted in giving Pennsylvania the most valuable anthracite basins of the country. The excellent bituminous coal (especially around Pittsburgh) is practically inexhaustible; iron ore has contributed materially to the prosperity of the state; petroleum and natural gas are important products of western Pennsylvania; her anthracite coal-basins are, however, the specialty. The anthracite tract covers an area of 472 sq. m., and is situated in the highland district between the Delaware and Susquehanna rivers. The proximity of coal and iron in such vast quantities has made Pennsylvania a great mining and manufacturing state; it leads in the manufacture of pig-iron. The successful boring for petroleum in 1859 produced an excitement hardly surpassed by the discovery of gold in California. There has been extensive utilisation of natural gas for heating and manufacturing purposes. Gold, silver, copper, and tin exist, but not in paying quantities; there are large zinc-works at South Bethlehem, and nickel is obtained in Lancaster county. The eastern part of the state is drained by the Delaware and its tributaries the Schuylkill and Lehigh. The Susquehanna, with its affluents, occupies the central drainage area. The greater part of western Pennsylvania is drained by the Alleghany and Monongahela rivers, uniting at Pittsburgh to form the Ohio. The climate is subject to extremes, and much modified by differences of elevation. Nearly one-fourth of the state is wooded; lumbering is one of the sources of wealth in the north, and farther south and west are great forests of hemlock, which maintain some of the largest tanneries in the world. The soil, except in the mountains, is rich and fertile. The mountain regions and the western plateau are well suited for grazing. The most important industries of Pennsylvania are mining and manufacturing. Shipbuilding is an important interest.
The first permanent settlement was made in 1643 at Chester by Swedes, whose colony of New Sweden was twelve years later conquered by the Dutch. In 1664 the English obtained possession, and the territory now called Pennsylvania was in 1681 granted by Charles II. to William Penn. In the revolutionary and in the civil war Pennsylvania took a prominent part. Many of the miners and ironworkers are of Irish, Hungarian, and Italian birth, and serious riots have not seldom occurred; a large proportion of the farmers are of German desaent, and still speak the patois known as 'Pennsylvania Dutch.' Philadelphia, chief manufacturing city of the Union, ranks third in population (1,293,697). Other cities are Pittsburgh (321,616), Allegheny (129,896), Scranton (102,026), Reading (78,961), Erie (52,733), Wilkesbarre (51,721), Harrisburg, the capital (50,167), Lancaster (41,459), Altoona (38,973), Johnstown (35,936), Allentown (35,416). Pop. of the state (1800) 602,365; (1840) 1,724,033; (1880) 4,282,891; (1900) 6,302,115.