Year Adopted: 1799.

Pennsylvania shares with Virginia, Kentucky and Massachusetts the designation "Commonwealth." The application of the term "Keystone State" to Pennsylvania cannot be traced to any single source. The word "keystone" comes from architecture and refers to the central, wedge-shaped stone in an arch, which holds all the other stones in place. It was commonly accepted soon after 1800.

Pennsylvania's State Flag is composed of the State Coat of Arms on a blue field. The first State Flag bearing the State Coat of Arms was authorized by the General Assembly in 1799. During the Civil War, many Pennsylvania regiments carried flags modeled after the U.S. Flag but substituted Pennsylvania's Coat of Arms for the field of stars. An act of the General Assembly of June 13, 1907, standardized the flag and required that the blue field match the blue of Old Glory. (ref; portal.state.pa.us, Symbols of Pennsylvania)

Pennsylvania's Coat of Arms forms the design on Pennsylvania's State Flag. In 1778, Caleb Lownes of Philadelphia prepared a state coat of arms. Heraldic in design, it consisted of a shield, which displayed the emblems of the State Seal --- the ship, plough, and sheaves of wheat; an eagle for the crest; two black horses as supporters; and the motto "Virtue, Liberty and Independence." An olive branch and a cornstalk were crossed below the shield.