How did the dred scott v. sanford supreme court case threaten free african americans living in the north?

Sandford, legal case in which the U.S. Supreme Court on March 6, 1857, ruled that a slave (Dred Scott) who had resided in a free state and territory (where slavery was prohibited) was not thereby entitled to his freedom; that African Americans were not and could never be citizens of the United States

Explanation:

affirmative action refers to the policies that take gender, race, or ethnicity into account in order to promote equal opportunity.

employers subject to title vii are prohibited from taking race or sex into account in any employment decisions. aa is a penalty for having any job group substantially statistically "underutilized" in any race or either sex. the employer must take steps to eliminate the underutilization, then stop, ending its aa efforts