Maryland Route 7 (MD 7) is a collection of state highways in the U.S. state of Maryland. Known for much of their length as Philadelphia Road, there are five disjoint mainline sections of the highway totaling that parallel U.S. Route 40 (US 40) in Baltimore, Harford, and Cecil counties in northeastern Maryland. The longest section of MD 7 begins at US 40 just east of the city of Baltimore in Rosedale and extends through eastern Baltimore County and southern Harford County to US 40 in Aberdeen. The next segment of the state highway is a C-shaped route through Havre de Grace on the west bank of the Susquehanna River. The third mainline section of MD 7 begins in Perryville on the east bank of the Susquehanna River and ends at US 40 a short distance west of the start of the fourth section, which passes through Charlestown and North East before ending at US 40, just west of Elkton. The fifth segment of the highway begins at South Street and passes through the eastern part of Elkton before reconnecting with US 40 east of Elkton and west of the Delaware state line. MD 7 is the old alignment of US 40 in northeastern Maryland. The route was first laid out early in colonial times and later formed part of the post road between Baltimore and Philadelphia (going further north to New York City and into New England to Boston) and between the northern and southern of the original Thirteen Colonies on the East Coast. The highway in Baltimore and Harford counties became a turnpike, constructed and operated by a private stockholder company in the early 19th century. The Maryland State Roads Commission (established 1908 - now the Maryland State Highway Administration within the Maryland Department of Transportation since the early 1970s) marked portions of what became known as the Philadelphia Road, close to Baltimore and between Perryville and Elkton for improvement as state roads in 1909. Those sections and the highway between Aberdeen and Havre de Grace were constructed as modern roads in the early to mid-1910s. The remainder of the highway was constructed in the 1920s and designated as US 40 in 1927. The high volume of traffic and the required continuous expansion of the highway led the old Maryland State Roads Commission to construct the modern Pulaski Highway (named for the foreign military volunteer of a Polish cavalry