Title of movie about slavery

It was a kind of presented as movie but it was all on a stage.

Topic is about slavery period in USA.

A young white skin lady who got a farm from her father. She owns black skin slaves who work for her in the farm. She was too kind and tried to help them (ideally). But she faced multiple issues (chocked by reality). She tried to teach them but many stood against her, on both sides! She learned about the issue the hard way.