Allegheny City, a manufacturing city of Allegheny county, Pa., opposite Pittsburgh, on the W. side of the Alleghany river, at its junction with the Monongahela; pop. in 1860, 28,702; in 1870, 53,180. The city contains many elegant residences of persons doing business in Pittsburgh. It has one weekly newspaper, and one semi-monthly and one monthly periodical. The Western theological seminary of the Presbyterian church was established here in 1827. Before the union it was under the control of the Old School Presbyterians. In 1868 there were 5 professors and 70 students, 935 graduates, and the endowment amounted to $184,800. The theological seminary of the United Presbyterian church, established in 1826, and the Allegheny theological institute, organized in 1840 by the synod of the Reformed Presbyterian church, are also situated here. In 1868 the former had 3 professors, 36 students, 426 graduates, and 2,000 volumes in the library. The western penitentiary, an immense building in the ancient Norman style, situated on the "common" of Allegheny City, was completed in 1827 at a cost of $183,000. In 1868 it had 463 inmates, employed in weaving, shoe-making, and the manufacture of cigars; earnings, $27,013. The city contains 12 schools, 2 national banks, 10 savings banks, 1 real estate bank, and 1 trust company; 4 rolling mills, employing 1,155 hands; 5 cotton mills, with 1,050 hands; 11 ale and beer breweries, averaging 20 men each; 6 founderies and machine shops, averaging 30 men each; 1 blast furnace, with 70 men; and 1 steel factory, with 250 hands.

The Pittsburgh locomotive works employ 380 hands and complete one locomotive a week. There are 45 churches, of which 16 are Presbyterian, 9 Catholic, 8 Methodist, 3 Baptist, 3 Lutheran, 2 Episcopal, and 1 each Congregational, Disciples', and Reformed. The charitable institutions are the home for the friendless, the widows' home association, the house of industry, and the orphan asylum. There is a soldiers' monument which cost $37,000. The city park contains an area of 100 acres. The assessed value of property in 1871 was $8,434,636.