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.
Were Harriet Tubman's parents slaves?
Yes, Harriet Tubman's parents were slaves.
What about Harriet Tubman's dad?
Yes, Ben Ross was a slave as well.

Question: How did they meet?
Self-contained rewrite: How did Harriet Green and Ben Ross meet?