Charles County Government offices are located at 200 Baltimore Street, La Plata MD 20646; phone: 301‑645‑0550.
Charles county lies on the Potomac river, its southern and western boundary, with Prince George's on the north and St. Mary's on the east. Between the two counties, a tongue of Charles extends to the Patuxent, and it was on this, at Benedict, that Ross's army disembarked for the march to Washington in 1814. The county was organized in 1658, and given the Christian name of the second lord proprietary. Its area is 460 square miles, and its great reach of water front on the Potomac, in a huge bend of which it is situated, gives it important resources in riparian products, oysters, Ash, water-fowl. The Wicomico river, Nanjemoy, Port Tobacco, and Mattawoman creeks are tributaries of the Potomac in this county. Tobacco is the principal crop, the average yield being 500 pounds to the acre, and corn and wheat are grown in considerable quantities. The Pope's Creek line of the Baltimore and Potomac railroad terminates at Pope's creek, on the Potomac. In the middle section of the county the land is level and in other parts its rolling surface is locally designated as "valleys." Port Tobacco, from colonial times the county seat, was succeeded a decade ago by La Plata, on the railroad. The entire village population of the county is very small. The United States Naval Proving Grounds, a government reservation at Indian Head in northwestern Charles, is where guns and projectiles for the navy are tested. Marshall Hall, nearly opposite Mt. Vernon, is closely connected with the memory of Washington, and is now an excursion resort. General William Smallwood was from Charles, and for a century his grave on the ancestral estate, near the old brick dwelling in which he and General Washington held Masonic meetings, was marked only by a walnut tree. On July 4, 1898, the Maryland Society of the Sons of the American Revolution unveiled a massive monument on the spot. This county was also the home of Thomas Stone, a signer of the Declaration of Independence; of Michael Jenifer Stone, a representative in the first Congress, who voted to place the seat of Federal government on the Potomac; of Governor John Hoskins Stone, distinguished at Long Island, White Plains, Princeton, Germantown; of Robert Hanson Harrison, Washington's military secretary, and a long list of able and brilliant men.