is the most western county in Maryland, and has Pennsylvania on the north. The windings of the Patowmack river separate it from Virginia on the south, and Sideling-hill Creek divides it from Washington county on the east. It contains 4899 inhabitants, including 258 slaves. Cumberland is its chief town.

ALLEGHANY County, in Pennsylvania, extends from the junction of the river of that name with the Ohio, where its chief town, Pittsburgh, is situated, to the New-York line. It contains 10,309 inhabitants, including 159 slaves.

ALLEGHANY Mountains, between the Atlantic ocean, the Mississippi river, and the lakes, are a long and broad range of mountains, made up of a great number of ridges, extending north-easterly and south-west-ally, nearly parallel to the sea coast, about 900 miles in length, and from 60 to 150 and 200 miles in breadth. Mr Evans observes, with respect to that part of these mountains which he travelled over, viz. in the back parts of Pennsylvania, that scarcely one acre in ten is capable of culture. This, however, is far from being the case in all parts of this range. Numerous tracts of fine arable and grazing land intervene between the ridges. The different ridges which compose this immense range of mountains, have different names in the different states, viz. the Blue Ridge, the North mountain or North ridge, or Devil's Back-Bone, Laurel ridge, Jackfish's mountains, and Kittatinny mountains. All these different and immense ridges, except the Alleghany, are broken through by rivers, which appear to have forced their way through solid rocks. This principal ridge is more immediately called Alleghany, and is descriptively named the Back-bone of the United States. From these several ridges proceed innumerable branches, or spurs.

The general name of the whole range, taken collectively, seems not yet to have been determined. Mr Evans calls them the Endless mountains; others have called them the Appalachian mountains, from a tribe of Indians, who live on a river which proceeds from this mountain, called the Appalachicola; but the most common name is the Alleghany mountains, so called, probably, from the principal ridge of the range. These mountains are not confusedly scattered, rising here and there into high peaks, towering each other; but run along in uniform ridges, scarcely half a mile high. They spread as you proceed south, and some of them terminate in high perpendicular bluffs: others gradually subside in a level country, giving rise to the rivers which run southerly into the gulf of Mexico.

ALLEGHANY River, in Pennsylvania, rises on the western side of the Alleghany mountains, and after running about 200 miles in a south-west direction, meets the Monongahela at Pittsburg, and both united form the Ohio. The lands on each side of this river, for 150 miles above Pittsburg, consist of white oak and chestnut ridges, and in many places of poor pitch pines, intermixed with tracts of good land, and low meadows. This river, and the Ohio likewise, from its head waters until it enters the Mississippi, are known and called by the name of Alleghany river, by the Seneca and other tribes of the Six Nations, who once inhabited it.