High Quality Content by WIKIPEDIA articles! USS Allegheny (1847) — the first United States Navy ship to be so named — was a large (989 long tons (1,005 t)) iron-hulled steamer that served as an American gunboat in the South Atlantic Ocean as well as in the European area. When the American Civil War occurred, Allegheny served the Union cause honorably, doing her part by supporting the Union Navy — because of her large size and operational condition — as a receiving ship.