Question: The Patapsco River is a 39 mi river in central Maryland, Patapsco is derived from which subgroup, of the Algonquian languages?
Context: The Patapsco Swinging Bridge is located in the Avalon/Orange Grove area of Patapsco Valley State Park in central Maryland, United States.  It is a suspension bridge consisting of a wooden deck supported by large cables.  The Patapsco Valley has a history of "swinging" bridges built for pedestrian travel from one side of the river to the other.  The Orange Grove Flour Mill was one such popular crossing and is where the current bridge now stands.  The first bridge was built by the Orange Grove Flour Mill for employees to cross the river.  The new swinging bridge, built by the Maryland Department of Natural Resources, is one of the most well known and most popular attractions at the Patapsco Valley State Park. The Patapsco Valley is a small valley surrounding the Patapsco River in central Maryland.  The region is known for its historical significance as a major economic and industrial center in the eighteenth and nineteenth centuries. The Patapsco River is a 39 mi river in central Maryland which flows into the Chesapeake Bay.  The river's tidal portion forms the harbor for the city of Baltimore.  With its South Branch, the Patapsco forms the northern border of Howard County, Maryland.  The name "Patapsco" is derived from the Algonquian "pota-psk-ut", which translates to "backwater" or "tide covered with froth." The Grist Mill Trail is a 5.0 mile long hiking and biking trail located in Patapsco Valley State Park in the Baltimore County side of the Patapsco Valley near Catonsville, Maryland.  The paved pathway runs parallel to the Baltimore and Ohio Railroad to the north, and the Patapsco River to the south. The Elkridge Site, or Elkridge Prehistoric Village Archeological Site, is an archaeological site near Elkridge in Anne Arundel County, Maryland.  It is located on a 20 ft terrace above the Patapsco River and extends 1200 ft along the river and inland from 20–400 feet.  It is the only known Woodland period riverine-oriented village site in the tidewater Patapsco River valley which has at least partially escaped the totally destructive forces of gravel quarrying.  The site appears to have been abandoned as a permanent village in the early 16th century. The Central Algonquian languages are commonly grouped together as a subgroup of the larger Algonquian family, itself a member of the Algic family.  Though the grouping is often encountered in the literature, it is an areal grouping rather than a genetic one.  In other words, the languages are grouped together because they were spoken near one another, not because they are more closely related to one another than to other Algonquian languages.  Within the Algonquian family, only Eastern Algonquian is a valid genealogical group. The Eastern Algonquian languages constitute a subgroup of the Algonquian languages.  Prior to European contact, Eastern Algonquian consisted of at least 17 languages, collectively occupying the Atlantic coast of North America and adjacent inland areas from what are now the Maritimes of Canada to North Carolina.  The available information about individual languages varies widely.  Some are known only from one or two documents containing words and phrases collected by missionaries, explorers or settlers, and some documents contain fragmentary evidence about more than one language or dialect.  Nearly all of the Eastern Algonquian languages are extinct.  Mi'kmaq and Malecite-Passamaquoddy have appreciable numbers of speakers, but Western Abnaki and Delaware are each reported to have fewer than 10 speakers after 2000. The Hockley Forge and Mill are a collection of colonial-era industrial buildings along the Patapsco River near modern Elkridge, Maryland.  Located at the river's head of navigation, the site is a flat section of land along the Patapsco River valley with steep embankments on either side.  At its 19th-century peak, the site held more than 30 industrial buildings. The Patuxent River is a tributary of the Chesapeake Bay in the state of Maryland.  There are three main river drainages for central Maryland: the Potomac River to the west passing through Washington, D.C., the Patapsco River to the northeast passing through Baltimore, and the Patuxent River between the two.  The 937 sqmi Patuxent watershed had a rapidly growing population of 590,769 in 2000.  It is the largest and longest river entirely within Maryland, and its watershed is the largest completely within the state. Powhatan or Virginia Algonquian is an extinct language belonging to the Eastern Algonquian subgroup of the Algonquian languages.  It was spoken by the Powhatan people of tidewater Virginia.  It became extinct around the 1790s after speakers were forced under duress to speak English.  The sole documentary evidence for this language is two short wordlists recorded around the time of first European contact.  William Strachey recorded about 500 words and Captain John Smith recorded only about 50 words.  Smith also reported the existence of a pidgin form of Powhatan, but virtually nothing is known of it.  Like many Algonquian languages, Powhatan did not have a writing system, so all that is left are the recordings from the 17th century and the piecing together that can be done using related Algonquian languages.
Answer: Eastern Algonquian languages