“The Old Line” refers to early Revolutionary War soldiers who hailed from Maryland and distinguished themselves in battle. In military parlance in the 1770s, a “line” meant a regiment. By 1780, Maryland’s line referred to itself as “old” in correspondence with military leaders, and the adjective refers both to the regiment’s length of service and its brave performance in war. Some sources attribute the phrase “The Old Line” to General George Washington, the commander in chief and later the first president of the fledgling United States, as it refers to Maryland’s distinguished regiment. The phrase particularly refers to the men who enlisted early in the war and fought in 1776 in a difficult battle on Long Island, and General Washington considered them heroes of the revolution and defenders of liberty for their staunch service.
From its beginnings as a reference to Maryland's Continental soldiers, The Old Line developed into The Old Line State, becoming the state of Maryland’s nickname. After all the members of the Old Line had died, the phrase “the Old Line” remained to honor their memory as well as their sacrifices during the war against British forces. The nickname calls to mind the honor and unblemished reputation earned by those early soldiers. General Washington expressed the opinion that they literally saved the Continental Army from complete destruction during the Battle of Long Island. The performance of soldiers in Maryland’s Old Line was said to equal that of the outstanding soldiers from Rhode Island, who served under Commander Nathaniel Greene, and possibly surpassed all other regiments.
Many soldiers from the 13 original colonies of the United States who were fighting for independence from the British were untrained and poorly outfitted. The opposite was true in the case of Maryland’s soldiers. The colony’s leaders agreed to send trained men to fight the Revolutionary War, and they were paid and fully dressed and equipped for the task. The leaders’ reasoning was that trained and outfitted men could perform the job better. Maryland’s Old Line was considered highly disciplined.
Another theory for the origin of the Old Line State nickname says it refers to the demarcation between two landowners in the 17th century, William Penn and Lord Baltimore. It was Lord Baltimore who gave Maryland its name, after the wife of his benefactor, England’s King Charles I. Her name was Henrietta Maria, and she was known as Queen Mary. Still another theory claims the Old Line State refers to the 19th-century Mason-Dixon Line. The Old Line State is the nickname that today is displayed on the Maryland state quarter.