Charles County, Maryland in the context of "Prince George's County, Maryland"

The Potomac River (/pəˈtoʊmək/ ) is in the Mid-Atlantic region of the United States and flows from the Potomac Highlands in West Virginia to Chesapeake Bay in Maryland. It is 405 miles (652 km) long, with a drainage area of 14,700 square miles (38,000 km), and is the fourth-largest river along the East Coast of the United States. More than 6 million people live within its watershed.

The river forms part of the borders between Maryland and Washington, D.C., on the left descending bank, and West Virginia and Virginia on the right descending bank. Except for a small portion of its headwaters in West Virginia, the North Branch Potomac River is considered part of Maryland to the low-water mark on the opposite bank. The South Branch Potomac River lies completely within the state of West Virginia except for its headwaters, which lie in Virginia. All navigable parts of the river were designated as a National Recreation Trail in 2006, and the National Oceanic and Atmospheric Administration (NOAA) designated an 18-square-mile (47 km) portion of the river in Charles County, Maryland, as the Mallows Bay–Potomac River National Marine Sanctuary in 2019.

Fairfax County, officially the County of Fairfax, is a county in the Commonwealth of Virginia. With a population of 1,150,309 as of the 2020 census, it is the most populous county in Virginia, the most populous jurisdiction in the Washington metropolitan area, and the most populous location in the Washington–Baltimore combined statistical area. The county seat is Fairfax; however, because it is an independent city under Virginia law, the city of Fairfax is not part of the county.

The county is part of the Northern Virginia region and forms part of the suburban ring of Washington, D.C., the nation's capital. The county is predominantly suburban with some urban and rural pockets. It borders Montgomery County, Maryland to its north, Falls Church, Alexandria, Arlington County, and Prince George's County, Maryland to its east, Charles County, Maryland to its southeast, Prince William County to its southwest, and Loudoun County to its northwest.

The Mallows Bay–Potomac River National Marine Sanctuary is a National Marine Sanctuary in the United States located in the Potomac River in Charles County, Maryland. It is best known for the "Ghost Fleet," 118 historic shipwrecks in Mallows Bay in the sanctuary's northeast corner which is the largest shipwreck fleet in the Western Hemisphere. They are among more than 200 shipwrecks in the sanctuary, some of which date as far back as the American Revolutionary War and others to the American Civil War.

In addition to shipwrecks, the sanctuary preserves historical sites related to Native Americans, some of them as much as 12,000 years old, as well as a lengthy span of United States history, including the American Revolutionary War, the American Civil War, steamboat and steamship activity during the Industrial Revolution, and what was once an important Potomac River fishing industry. It also protects sites dating as far back as the 17th century related to African-American history, as well as an ecologically and biologically important area of the Potomac River and its Maryland shoreline that supports many species of plants and animals.

Colonel Thomas Lee (c. 1690 – November 14, 1750) was a planter and politician in colonial Virginia, and a member of the Lee family, a political dynasty. Lee became involved in politics in 1710, serving in both houses of the Virginia General Assembly, and also held important positions as Naval Officer for the Northern Potomac Region and agent for the Northern Neck Proprietary. After his father died, Lee inherited thousands of acres of land as well as enslaved people in then-vast Northumberland and Stafford Counties in Virginia as well as across the Potomac River in Charles County, Maryland. These properties were developed as tobacco plantations. Northumberland County was later subdivided, so some of Lee's properties were in present-day Fairfax, Fauquier, Prince William, and Loudoun counties and counties in the present-day Northern Neck of Virginia.

When Lee married Hannah Harrison Ludwell in 1722, he benefited from the connections of the already established Harrison family of Virginia. A year later, he would become a member of the House of Burgesses. Arson destroyed Lee's home, he used money from Caroline of Ansbach and Britain to build Stratford Hall overlooking the Potomac River. Four years later, in 1733, he was appointed to the Governor's Council, the upper house of the General Assembly. In 1747, he founded the Ohio Company of Virginia with fellow Virginian colonists who wished to expand Virginia's territory into the Ohio River Valley. For less than a year, in 1749 until his death in 1750, Lee served as the de facto royal governor of Virginia in place of the absent William Gooch.

La Plata (/ləˈpleɪtə/ lə-PLAY-tə) is a town in Charles County, Maryland, United States. The population was 10,159 at the 2020 census. It is the county seat of Charles County.

Southern Maryland, also referred to as SoMD, is a geographical, cultural and historic region in Maryland composed of the state's southernmost counties on the Western Shore of the Chesapeake Bay. According to the state of Maryland, the region includes all of Calvert, Charles, and St. Mary's counties and the southern portions of Anne Arundel and Prince George's counties. It is largely coterminous with the region of Maryland that is part of the Washington metropolitan area. Portions of the region are also part of the Baltimore Metropolitan Area and the California-Lexington Park Metropolitan Statistical Area. As of the 2020 Census, the region had a population of 373,177. The largest community in Southern Maryland is Waldorf, with a population of 81,410 as of the 2020 Census.

Initially inhabited by the indigenous Piscataway people, the first European settlement in Southern Maryland (and the state as a whole) was established in St. Mary's City in 1634. While the settlement was intended to be a Catholic refuge, religious strife was prominent in Maryland's early years. The passage of the Maryland Toleration Act in 1649 resulted in St. Mary's City being cited as the birthplace of religious freedom in North America. The area developed an agricultural economy based on tobacco with labor sourced from indentured servants and slaves. The War of 1812 saw military action in the region during the British campaign to capture Washington, while the American Civil War saw the end of slavery in Maryland and John Wilkes Booth fleeing through the region following the Assassination of Abraham Lincoln. Much of the area remains rural with agriculture still playing a large role in the region's economy. Despite this, the region has seen large suburban growth and development in the late 20th and early 21st centuries as urban sprawl from nearby Washington, D.C., expands southward.

Mallows Bay is a small bay in Maryland, on the left bank of the Potomac River, in Charles County, Maryland, United States. The bay is the location of what is regarded as the "largest shipwreck fleet in the Western Hemisphere" and is described as a "ship graveyard."

Mallows Bay is in the northeast corner of the Mallows Bay–Potomac River National Marine Sanctuary, which the National Oceanic and Atmospheric Administration designated on September 3, 2019. The bay lies in the northeast corner of the 18 square miles (47 km) of Potomac River waters included in the sanctuary.

Maryland Route 210 (MD 210) is a state highway in the U.S. state of Maryland. Known as Indian Head Highway, the highway runs 20.86 miles (33.57 km) from Potomac Avenue in Indian Head north to the District of Columbia boundary in Forest Heights, where the highway continues into Washington, D.C., as South Capitol Street. MD 210 is a four- to six-lane divided highway that connects Washington, D.C., with the suburban communities of Oxon Hill, Fort Washington, and Accokeek in southwestern Prince George's County, and Bryans Road and Indian Head in northwestern Charles County. The highway also provides access to Fort Washington Park and Indian Head Naval Surface Warfare Center and, in conjunction with MD 228, connects Waldorf with Interstate 95 (I-95)/I-495 and I-295.

Indian Head Highway was constructed by the U.S. federal government as a military access highway in the mid-1940s to connect Washington with the Indian Head Naval Proving Ground and Fort Washington. The previous highway between Washington, D.C., and Indian Head was Livingston Road, which was traced in the late 18th century and improved in the 1920s and early 1930s as MD 224. The new highway incorporated several sections of meandering MD 224 into its straight path. Indian Head Highway was fully designated MD 210 in the mid-1950s when the road was transferred from federal to state control. MD 210 was expanded to a divided highway in Forest Heights in the late 1940s and south through Fort Washington in the 1960s. Another section of divided highway was completed through Charles County in the late 1960s and early 1970s. The final divided highway section was completed through Accokeek in the mid-1980s. MD 210 was connected with I-295 in 1989 and its interchange with I-95/I-495 was reconstructed in the mid-2000s. The Maryland State Highway Administration has long-term plans to replace the highway's major intersections with interchanges from Oxon Hill south through Fort Washington.