 In 1949, the state highway was relocated and a new bridge was constructed near Port Tobacco, replacing a dangerous curve and one-way bridge.MD 6 was widened and resurfaced with bituminous concrete through downtown La Plata in 1951.In 1955 and 1956, MD 6 from US 301 west to McConchie was reconstructed as the westbound direction of an ultimate divided highway that was proposed.