PENNSYLVANIA (ante), one of the thirteen original states of the union, lies between 39" 43' and 42° n., and 74° 40' and 80° 36' w.; that part which borders on lake Erie extends to 42° 15' north.. It has lake Erie and New York Cu the n.. New, York and New .Tersey, by the Delaware river, on the c., Delaware, Maiyland, and West Virginia on the s., aml \test Virgin'a and Ohio on the west. From its place among the thirteen original state-, it was called the Keystone state. Its extreme dimensions are 315 rn. e. and w., and 100 in. n. and s., about 43.000 sq.m. It is divided into 66 counties. The population by fec'end census was, in 1790, 484,373; 1E00, 602.365; 1810. 810,091; 181:0, 1,047,507; 1830, 1,348,233; 1S40, 1,724,033; 1850, 2,311,786; 1860, 2,EC6,215; 1870, 3,521,951; 1880, 4,282,738.
The state is hilly end mountainous in the center, rolling in the w., level in the s.e. A number of parallel ridges, with a maximum height of 2,500 ft., cross it from me. to s.w.; they are all members of the Appalachian system and cover about one-fourth of the entire area of the state. -Next w. of the South mountain, on the Delaware, below Easton, is the Kittatinny or Blue mountains; then the Broad mountains, s of the n. hranch of the Susquehanna; the Tuscarora w. of that river; the Sidling hills s. of the Juniata; the Alleghany mountains; the chestnut and Laurel Dill ridges. The breadth of the entire mountain system of the state exceeds £00 m.; it forms numerous beautiful and fertile valleys, and incloses the richest coal fields and iron deposits in the union; the valleys mostly conform to the general trend of the mountains; the rivers follow similar lines, but often traverse the valleys obliquely. The Delaware enters the state about hit. 42°, and continues front that point throughout its course to Marcus Hook, as the boundary between Pennsylvania and New Jersey. The river was named after Lord de la Warr, who visited the bay in 1610; the Indians called it Poutaxas, Mariequetoh, ilitAri.ykitton, etc. Its length is 300 miles. At the Water Gap y breaks through a nar row gorge, whose sides rise perpendicularly to near 1200 ft., and presents a truly grand spectacle. At Easton it receives the Lehigh, DO in. long, a beautiful, rapid and romantic stream, rising in the coal region; the Lehigh Water Gap. below Mauch Chunk, is a very. pict uresque spot. Mauch Chunk, Allentown, and Bethlehem are on the Lehigh. Sixty in. s. of Easton the Delaware, with a fall of about 160 ft., reaches tide-water at Trenton: 35 in. further s.w. passes Philadelphia, below which city it receives the Schuylkill (Indian name, Mai-nai-unk). a stream 120 in. long, rising in the coal regions, peculiarly rich in tributaries, which passes Pottsville, Heading, Norristown, and Mans pink. Chester, New Castle, and Delaware City, are below Philadelphia. (For Delaware
hay. see MAnYmkNn and NEw Jr.nsEv). The Susquehanna. though its n.e. branch rises in New York, is emphatically the river of Pennsylvania; besides the n.e. branch it consiAs of the w. branch and the .Vuniata, and drains about 22.000 sq.m. The n.e. branch, after 'lowing 250 m. from its rise in Otsego lake, and receiving the Chemung or Tioga and the Lackawanna, through the beautiful Wyoming valley, unites below Northumberland with the great w. branch (175 In. long from its rise in Cambria co.), pursues its course s., until it receives the .Tuniata (150 in. long from its rise in the eastern slopes of the Alleghany mountains), and theft turtling s.e. empties, after an entire course of 500 m., into the Chesapeake bay. This river and its tributaries, justly famed for great beauty, pass through the richest and most fertile regions of the state. The two great rivers w. of the Alleghany mountains, junction forms the Ohio, are the Alleghany and Mon ongahela; the former rising in Potter co., flows 50 in. n.w. into New York, and turning s.w. re-enters Pennsylvania, in Warren eo., receives the Clarion river, Red Bank creek, the Kiskiminetas or Conemaugh on the left, and French and Conewango creeks on the right, all very important streams; the Allegheny, from the point at which it re-enters the state, to that of its junction with the Monongahela at Pittsburg. is 180 nr, long. The Indians called both the Ohio and the Allegheny by the latter tunic, the former desig nating in the language of the Delawares Fair Water," just as the latter had the same meaning in that of the Seneeas.—The Monongahela is formed by two brunches, the Monongahela proper and the Cheat river, both of which rise and flow n. in Virginia for a distance of 100 in.; these branches unite in Fayette co., Penn., end the river then flows n. 80 m. ; at McKeesport it receives the Youghiogheny from the s.e., about 100 in. long, and in a n.w. course of 18 m. ; forms by the confluence with the Allegheny, which meets it from the n., the Ohio river at Pittsburg. The Ohio flows 25 in. to the mouth of the Big Beaver (the recipient of several tributaries, which together drain an area of about 6,000 sq.m.), and then turning s.w. leaves the state in Beaver county. Almost all the rivers break through the mountain chains, and give natural access to its mineral and agricultural wealth. The Delaware is navigable for vessels of largest size tai Philadelphia; for steamboats to Trenton; for smaller craft Easton. The Susque hanna is not navigable in the state for steamboats, but both the Allegheny and Mononga hela are navigable for 60 in. from their continence, while the Ohio is one of the great water ways to the Mississippi. There are no great lakes in Pennsylvania, but it borders bike Erie for 45 in., and has an excellent harbor at Erie.