50127
He also urged the erection of fortifications on the Virginia side of the Potomac River to protect the southern terminuses of the Chain Bridge , Long Bridge , and Aqueduct Bridge .
 organization: Potomac
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Potomac 
Answer:
 organization: Potomac