One of the Middle Atlantic states of the United States. It is bordered by New Jersey, across the Delaware River, Delaware, Maryland, West Virginia, Ohio, and Lake Erie and New York). Area, 45,333 sq mi (117,412 sq km). Pop. (2000) 12,281,054, a 3.4% increase since the 1990 census. Capital, Harrisburg. Largest city, Philadelphia.  Nickname, Keystone State. Motto, Virtue, Liberty, and Independence. State bird, ruffed grouse. State flower, mountain laurel. State tree, hemlock. The Pittsburgh and Philadelphia metropolitan areas, situated at opposite ends of the state and dominating the commercial and industrial life of their regions, present startling contrasts in production and culture.  Agriculture is concentrated in the fertile counties of the southeast, and prized farmlands lie in the Great Appalachian Valley, rich with limestone soils; here the Pennsylvania Dutch farmer built a culture that is identified with the bountiful agrarian life. Principal agricultural products include dairy products, cattle, hay, corn, wheat, oats, mushrooms, poultry, potatoes, and fruit. The great forests and lush vegetation that once covered the entire state were transformed during the Carboniferous period into deposits of anthracite coal in the northeast and extensive bituminous beds in the west. Large areas of woodland remain and, in some isolated sections, have retained an almost primitive wildness. Of the many historic sites and parks that have been preserved, those under federal ownership include Fort Necessity National Battlefield, Gettysburg National Military Park, and Independence and Valley Forge national historical parks. Harrisburg, the state capital, is located between the metropolitan areas of Philadelphia, the largest city, and Pittsburgh.     Columbia Encyclopedia, Sixth Edition, Copyright (c) 2003.