Frederick is a city in north-central Maryland, United States. It is the county seat of Frederick County, the largest county by area in the state of Maryland. Frederick is an outlying community of the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area, which is part of a greater Washington-Baltimore-Northern Virginia, DC-MD-VA-WV Combined Statistical Area. The city's population was 65,239 people at the 2010 census, making it the second largest incorporated area in Maryland behind Baltimore.
Frederick is home to Frederick Municipal Airport (FDK), which primarily accommodates general aviation traffic, and to the U.S. Army's Fort Detrick, the largest employer in the county. Frederick is also home to BP Solar, which is the second-largest employer in the county (March 2010, BP Solar laid off hundreds of employees due to setbacks).
“Frederick Town” was laid out by Daniel Dulany — a land speculator — in 1745; it was settled by a German immigrant party led by a young German Reformed schoolmaster from the Rhineland Palatinate named Johann Thomas Schley (d. 1790), who came to the Maryland colony with his wife, Maria Winz. Schley built the first house of the new town; as late as the 20th century, it stood at the northwest corner of Middle Alley and East Patrick Street. The settlement was founded upon a tract of land granted by Dulany on the banks of Carroll Creek. Within three years, the settlement had become the county seat of Frederick County. It is uncertain which Frederick the town was named for, but the likeliest candidates are Frederick Calvert, 6th Baron Baltimore (one of the proprietors of Maryland), Frederick Lewis, Prince of Wales, and Frederick "The Great" of Prussia. Most sources favor Calvert.