Why were Northerners outraged by the Dred Scott decision?

The Northerners feared that the Dred Scott decisión would allow the spread of slavery throughout the country.

Explanation:

It was a ruling by the US Supreme Court which stayed that the US Constitution was not mean to include citizenship for black people.

c 3 branches because idk why they had 3 well when:

you think of it there are still contrys with 3