# Keystone symbol

The keystone symbol is the name commonly given to the de-facto state emblem of Pennsylvania. It is a stylized keystone (or capstone), an architectural term for a wedge-shaped stone placed at the top of an arch. The shape consists of two isosceles trapezoids, each with the smaller side facing downward, with one being smaller, more flat, and placed on top of the other. The symbol alludes to Pennsylvania's official nickname, The Keystone State. Although the symbol has not been designated as the official state emblem, it is widely used by the Pennsylvania government and by individuals.
* Use as a bullet point on modern Pennsylvanian license plates
* Use on state quarter
* Use on official state route markers

## Usage

Each agency of the Pennsylvania government uses the keystone symbol on its official logo. It is also used on various logos, such as that of the Pennsylvania Railroad, Heinz Company, Little League Baseball, and National Honor Society — both worldwide, and founded in Pennsylvania.
Keystone symbols are extremely common in military heraldry. It can be found on the badge of the Pennsylvania Army National Guard, the Pennsylvania Air National Guard, and the now-disbanded Pennsylvania State Guard. Many parts of the Pennsylvanian and United States national army also include keystone symbols on their insignia.
The flag of Shenango Township (in Lawrence County, Pennsylvania) has a keystone symbol on it. The shield is shaped like a keystone symbol on the de-facto coat of arms of the city of Allentown, Pennsylvania, which is placed on the city's official flag and seal. The seal of Keystone Heights, Florida also has a keystone symbol on it.
In 2017 the "Keystone Flag" was designed by Tara Stark, a Pennsylvania resident. The flag incorporates the keystone into a tricolor design using the colors on the coat of arms of Pennsylvania as an intentional callback to the symbolism of the existing flag. The design gained significant attention on social media, but is not currently adopted.
The bookplate of the University of Pennsylvania is in the shape of a keystone symbol. The shield of the coat of arms of the Keystone Central School District is shaped like a keystone symbol.
The seal and burgee of the Erie Yacht Club in Erie, Pennsylvania both have keystone symbols on them.

## History

In September 1899, a military parade in Philadelphia featured a choir of 3,200 school-children and teachers that were arranged to display three keystone symbols with the letters "GAR" on them (standing for Grand army of the Republic). By the 1910s, the symbol was somewhat popular, and was used often enough that the average person could recognize it.
* Heinz bottle c. 1893
* 1911 Pennsylvanian license plate
* 1915 Women's suffrage clothing pin featuring a keystone symbol
Shortly after World War I, the Department of Highways (now part of PennDOT) created a system of road signs called keystone markers. These signs were in the shape of the keystone symbol, and were usually blue with a yellow border but could vary due to cultural reasons. These signs used to number in the thousands, but as of 2010, only around 600 exist state-wide. Today, "keystone marker" can informally refer to the modern state route markers.