Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Cahokia Mounds State Historic Site' has mentioned 'United States' in the following places:
Occurrence Sentence Text Source
Cahokia was the largest and most influential urban settlement of the Mississippian culture, which developed advanced societies across much of what is now the central and southeastern United States, beginning more than 1,000 years before European contact.
It is also one of the 24 UNESCO World Heritage Sites within the United States.
Their settlements ranged across what is now the Midwest, Eastern, and Southeastern United States.
[26] If the highest population estimates are correct, Cahokia was larger than any subsequent city in the United States until the 1780s, when Philadelphia's population grew beyond 40,000.
This is the only such self-contained site in Illinois and among 24 World Heritage Sites in the United States in 2009.
Located in Collinsville, Illinois near the city of St. Louis, this largest pre-Columbian settlement north of Mexico is the pre-eminent example of a cultural, religious, and economic centre of the Mississippian culture (800xe2x80x931350), which extended throughout the Mississippi Valley and the south-eastern United States.