Allegheny County Seal
The Allegheny County Seal derives directly from the seal of the Commonwealth of Pennsylvania, and is the same as the Pennsylvania State Seal in all essential details.
The origins of the Pennsylvania Seal hearken back to colonial days, when the seals of the colonial counties of Pennsylvania were formed by mounting a distinguishing crest upon the Penn coat-of-arms. The crest of the Chester County seal was a plough; the crest of Philadelphia County was a ship under full sail; and the crest of Sussex County, Delaware, which formed a part of Pennsylvania when a province, was a sheath of wheat. The seal of the City of Philadelphia bore on its shield both the sheaf of wheat and the ship in full sail.
The present form of the Allegheny County Seal was decreed by the Pennsylvania Legislature more than 100 years ago, and the colonial emblems have remained, taking on new significance.
The ship symbolizes the vast commercial traffic which Allegheny County carries on with the rest of the world.
The plough signifies subterranean and earth-related resources, thus emblematizing the agricultural and mining activities of the county, and would also include the early glassmaking and other domestic-related county industries. The sheaves of wheat typify the county's harvests, both agricultural and as the result of human industry and initiative in the areas of mining, manufacturing, and intellectual production.
Surrounding and surmounting the seal are a cornstalk, signifying abundance; an olive branch, which stands for peace; and an eagle, which denotes sovereignty.