What is the historical context of frederick douglass on dred scott decision

The historical context of Frederick Douglass on Dred scott decision is that he was the leader of the anti-slavery movement in north and he was a escaped slave.  

Explanation:

Frederick Douglass on the 'Dred scott decision' is that many of the formers are enslaved on the eve of liberty. He plays a role in the struggling on the future of the people managed to throw of slavery shackles. He took the opposite view 'asserting blackness' was no bar to belonging. He viewed his 'citizenship' as a evident to spoke out as american, as a man, as a coloured man of both "Anglo Saxon and African descent".  

Yeah i’ll call ya tomorrow but i’m not sure if you wanna talk about it later