Conversation so far:
Where was Harriet Tubman born?
As with many slaves in the United States, neither the exact year nor place of Harriet Tubman's birth is known, and historians differ as to the best estimate.
Who were Harriet Tubman's parents?
Harriet Tubman was born Araminta Minty Ross to enslaved parents, Harriet Green and Ben Ross.

Question: Were they slaves?
Self-contained rewrite: Were Harriet Tubman's parents slaves?