||Origin: Frederick County was created in 1748 from Baltimore and Prince George's counties (Chapter 15, Acts of 1748). The County probably was named after Frederick Calvert (1731-1771), sixth and last Lord Baltimore, who was the Proprietor of Maryland from 1751 until his death in 1771 at Naples, Italy.
County Seat: Frederick , MD 21701
Form of Government: County Commissioners
1990 census: 150,208
2000 census: 195,277