Conversation so far:
Who did Tubman marry?
she married a free black man named John Tubman.
When did they marry?
Around 1844.
Did they have any kids?
CANNOTANSWER.
Where did they live?
little is known about him or their time together.

Question: What else is significant?
Self-contained rewrite: Besides Harriet Tubman and John Tubman being married, what else is significant?