Individual #Potomac_River__Potomac  a river in the east central United States; rises in the Appalachian Mountains of West Virginia and flows eastward to the Chesapeake Bay
  instance of:  river
  part of:  East_USA  the region of the United States lying north of the Ohio River and east of the Mississippi River
     part of:  USA__United_States_of_America__United_States__America__US__U.S.__U.S.A.  North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776
        part of:  North_America  a continent (the third largest) in the western hemisphere connected to South America by the Isthmus of Panama
           part of:  northern_hemisphere  the hemisphere north of the equator
           part of:  western_hemisphere__westernhemisphere__occident__New_World  the hemisphere that includes North and South America
           part of:  the_Americas__America  North and South America

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