OHIO, a north central state of the United States of America, lying between latitudes 38° 27′ and 41° 57′ N. and between longitudes 80° 34′ and It is bounded N. by Michigan and Lake Erie, E. by Pennsylvania and by the Ohio river which separates it from West Virginia, S. by the Ohio river which separates it from West Virginia and Kentucky, and W. by Indiana. The total area is being water surface.
Physiography.—The state lies on the borderland between
the Prairie Plains and the Alleghany Plateau. The disturbances
among the underlying rocks of Ohio have been slight, and
originally the surface was a plain only slightly undulating; stream dissection changed the region to one of numberless hills and valleys; glacial drift then filled up the valleys over large broken areas, forming the remarkably level till plains of north-western Ohio; but at the same time other areas were broken by the uneven distribution of the drift, and south-eastern Ohio, which was unglaciated, retains its rugged hilly character, gradually merging with the typical plateau country farther S.E. The average elevation of the state above the sea is about 850 ft., but extremes vary from 425 ft. at the confluence of the Great Miami and Ohio rivers in the S.W. corner to 1540 ft. on the summit of Hogues Hill about E. of Bellefontaine in the west central part.
Population.—The population of Ohio in the various census
years was: (1800) 45,365; (1810) 230,760; (1820) 581,434; (1830) 937,903; (1840) 1,519,467; (1850) 1,980,320; (1860) 2,339,511; (1870) 2,665,260; (1880) 3,198,062; (1890) 3,672,316; (1900) 4,157,545; (1910) 4,767,121. In 1900 and 1910 it ranked fourth in population among the states. Of the total population in 1900, 4,060,204 or 97·6% were white and 97,341 were coloured (96,901 negroes, 371 Chinese, 27 Japanese and 42 Indians). Of the same total 3,698,811 or 88·9% were native-born and 458,734 were foreign-born; 93·8% of the foreign-born consisted of the following: 204,160 natives of Germany, 65,553 of Great Britain, 55,018 of Ireland, 22,767 of Canada (19,864 English Canadian), 16,822 of Poland, 15,131 of Bohemia, 11,575 of Austria and 11,321 of Italy. In 1906 there were 1,742,873 communicants of different religious denominations, over one-third being Roman Catholics and about one-fifth Methodists. From 1890 to 1900 the urban population (i.e. population of incorporated places having 4000 inhabitants or more) increased from 1,387,884 to 1,864,519, and the semi-urban (i.e. population of incorporated places having less than 4000 inhabitants) increased from 458,033 to 549,741, but the rural (i.e. population outside of incorporated places) decreased from 1,826,412 to 1,743,285. The largest cities are Cleveland, Cincinnati, Columbus (the capital), Toledo, Dayton, Youngstown, Akron, Canton, Springfield, Hamilton, Lima and Zanesville.