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
Province of Maryland Province of Maryland The Province of Maryland was an English and later British colony in North America that existed from 1632 until 1776, when it joined the other twelve of the Thirteen Colonies in rebellion against Great Britain and became the U.S. state of Maryland. Its first settlement and capital was St. Mary's City, in the southern end of St. Mary's County, which is a peninsula in the Chesapeake Bay and is also bordered by four tidal rivers. The province began as a proprietary colony of the English Lord Baltimore, who wished to create a haven for English Catholics in