Pennsylvania's coat of arms is not used in the official capacity of the state seal, but it's a familiar symbol of the commonwealth of Pennsylvania and appears on countless documents and publications. The coat of arms also forms the design on Pennsylvania's state flag, and includes the state motto: "Virtue, Liberty, and Independence."

Based on a 1778 design by Caleb Lownes of Philadelphia, the Pennsylvania coat of arms features a shield crested by an American bald eagle, flanked by horses, and adorned with symbols of Pennsylvania's strengths - a ship carrying state commerce to all parts of the world; a clay-red plough (a symbol of the Pennsylvania's rich natural resources); and three golden sheaves of wheat, representing fertile fields and Pennsylvania's wealth of human thought and action. An olive branch and cornstalk cross limbs beneath - symbols of peace and prosperity. The state motto ("Virtue Liberty and Independendence") appears festooned below.

Provincial Pennsylvania's coat of arms was that of the Penn family (see name origin). The coat of arms first appeared in an official capacity on paper money issued in 1777. This first Pennsylvania coat of arms was nearly identical to the state seal (minus the inscription).

Source:

Pennsylvania - Symbols: PA Historical & Museum Comm.
State Symbols: Hello Pennsylvania
Pennsylvania Coat of Arms in Bronze: James E. Frizzell

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Pennsylvania state motto