PITTSBURGH (sometimes, but erroneously, spelled Pitts burg), the second largest city of Pennsylvania, U.S.A., and the county seat of Allegheny county, on the Allegheny, Monongahela and Ohio rivers, 440m. by rail W. by S. of New York city, 348.5m. W. by N. of Philadelphia, 368m. N.W. of Washington and 468m. E. by S. of Chicago. Pop. (1910, after annexation of Allegheny) 533,905, and (1920) 588,343, and increased by the 1930 census to 669,817. In previous census years, the population was as follows : (1800), 1,565; (182o), 7,248; (1840), 21,115; (1860), (1880), 156,389; (1890), 238,617; (i9oo), 321,616. After the 1920 census was taken, and up to 1927, parts of Chartiers, Re serve and Lower St. Clair townships, Frick Woods and St. Clair, Carrick, Knoxville and Westwood boroughs, with a population of 30,00o were annexed. Area 31,474.43u. or 49-179 square miles. The chief business area, called the golden triangle, covers 974.3ac. or 1.52 sq.m. Population, including suburbs, 1,574.75 sq.m. (1930), 1,953,668, and of Allegheny county (1930), 1,374,410. As a city Pittsburgh ranks tenth and as a metropolitan area seventh in the United States. The sesquicentennial anniversary (1758 1908) of the city was elaborately observed in 1908.
In the city, illiteracy is 2.6% compared with State average 3.1% but the illiteracy of native white is 0.3 compared with State average o.5. The negro population was (1930) 8.o% or 54,983. Orientals are few. Of the 109,072 (1930) foreign born, 6,293 were natives of England, 3,130 of Scotland, 11,246 of Ireland, 1,117 of Wales, 986 of Sweden, 14,409 of Germany, 15,251 of Poland, 9,224 of Russia, 3,937 of Austria, 2,235 of Hungary, 6,67o of Czechoslovakia, 4,132 of Yugoslavia, 3,258 of Lithuania, 18,154 of Italy, 1,683 of Canada and 7,347 miscellaneous. Pitts burgh is served by the Pennsylvania, the Baltimore and Ohio, the New York Central (Pittsburgh and Lake Erie), the Buffalo, Rochester and Pittsburgh, the Bessemer and Lake Erie, and the Pittsburgh and West Virginia railways, and by boats on the Ohio, Monongahela and Allegheny rivers.
Picturesque rolling plateaux, the three rivers and narrow valleys from which rise high hills or precipitous bluffs, are the principal natural features of the district over which the city extends. Re
tail houses, wholesale houses, banks, tall office buildings, hotels, theatres and railway terminals are crowded into the angle, or "The Point," formed at the confluence of the Allegheny and Monongahela rivers, with Fifth avenue as the principal thorough fare, especially for the retail houses, and Fourth avenue as the great banking thoroughfare. Factories extend for several miles along the banks of all three rivers into the tributary valleys, and are the cause of Pittsburgh's former nickname, "The Smoky City." With the practical elimination of smoke through the use of natural gas, a more recent nickname is the "Steel City" or "Elec tric City." The more attractive residential districts are on the plateau in the eastern portion of the district between the Allegheny and Monongahela rivers and on the undulating hills overlooking the Allegheny river from the north. Overlooking the Mononga hela river is Schenley park (about 422ac.), the first city park, of which about 400ac. were given to the city in 1890 by Mrs. Mary E. Schenley. About 2M. to the north, overlooking the Allegheny river, is Highland park (about 366ac.), which contains the city reservoirs and a picturesque lake. Not far from Schen ley park are Homewood and Calvary cemeteries; and the Frick woods (2iac.) donated for a park by the late Henry C. Frick; and not far from Highland park is Allegheny cemetery, also overlooking the Allegheny river. Across the Allegheny river, in the Allegheny district, are the beautiful Riverview park (240 ac.) in which is the Allegheny observatory, and West park (about ioo acres). In 1927 the county acquired the North and South parks (each 1,2ooac.). Sixteen bridges span the rivers. The county in 1923 completed twin tunnels—each tube 25ft. wide and 5,889ft. long—at a cost of $6,000,000 under Mt. Washington to connect the southern hill with the city by a high-level bridge over the Monongahela.