Assertion: slum | /r/AtLocation | the united states
Facets:
value: before the early 20th century
type: TEMPORAL
Source sentences:
text: Slums were common in the United States and Europe before the early 20th century.
text: It is worth acknowledging that slums were common in Europe and the United States between the 18th and 20th centuries.
text: Slums were common in the United States and Europe before the early 20th century.