Which U.S. state is nicknamed the "Old Line State"?

Maryland is called the Old Line State to honor the heroic fighting of a Maryland regiment, or line, in the American Revolution. George Washington was an early source of reference to the “old line” that protected his retreat from the Battle of Long Island. The ties between the “old line” and the State of Maryland grew gradually throughout the 1800's and early 1900's.

The rationale behind naming the Maryland regiment the “old line” is somewhat unclear. It likely refers to their comparative discipline and experience—visible prior to the Battle of Long Island and proven during their cover of the Continental Army’s retreat.

The name transition occurred after the Civil War, when the goal to reunite the state’s inhabitants required looking beyond recent events. The heroic efforts of the Maryland Line at the Battle of Long Island provided an opportunity to connect the state with a foundational event in U.S. history. Businesses began to preface their names with “old line,” such as “Old Line Real Estate” or “Old Line Legal and Reserve.”

Those sentiments were codified in the twentieth century, when histories in the 1920–30's used "Old Line State" as a stand-in for Maryland. The Maryland Manual Supplement, published in 1975–76, was the first to state the connection explicitly, noting "Old Line State" as a nickname for Maryland.