Maryland Route 6 (MD 6) is a state highway in the U.S. state of Maryland. The state highway runs 47.36 miles (76.22 km) from a dead end at the Potomac River in Riverside east to MD 235 in Oraville. MD 6 connects several small communities in southern Charles County and northern St. Mary's County with U.S. Route 301 (US 301) in La Plata, the county seat of Charles County, and MD 5 in Charlotte Hall. The state highway also provides access to multiple historic sites around Port Tobacco, the original county seat of Charles County. MD 6 was one of the original highways numbered by the Maryland State Roads Commission in 1927. The state highway was constructed from La Plata to Riverside in the late 1910s and early 1920s. The La Plata–Charlotte Hall section of the highway was built in the mid-1920s