Frederick County, Maryland Frederick County, Maryland Frederick County is located in the northern part of the U.S. state of Maryland. As of the 2010 U.S. Census, the population was 240,336. The county seat is Frederick. Frederick County is included in the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area. Like other outlying sections of the Washington metropolitan area, Frederick County has experienced a rapid population increase in recent years. It borders the southern border of Pennsylvania and the northeastern border of Virginia. The county is home to Catoctin Mountain Park (encompassing the presidential retreat Camp David) and to the U.S. Army's Fort Detrick. It has also
Maryland in the American Revolution occurred in Maryland itself (although the British Royal Navy fleet passed through and up the Bay to land troops at the "Head of Elk"), to attack the colonies' capital city, this did not prevent the state's soldiers from distinguishing themselves through their service. General George Washington counted the "Maryland Line" regiment who fought in the Continental Army especially the famed "Maryland 400" during the Battle of Brooklyn in August 1776, outside New York Town as among his finest soldiers, and Maryland is still known as "The Old Line State" today. During the war itself, Baltimore Town served as the temporary