Scott v. Sandford was the Supreme court case in which SC ruled that the slave owners can take their slave into western territories. It negated the principle of popular sovereignty. This decision caused tensions on the issue of slavery in the US.
Plessy vs. Ferguson was supreme court case in which the court ruled that the racial segregation was constitutional as long as the segregated facilities were equal in quality. It came to be known as "separate but Equal". This case was important because allowed the segregation to become law in US. And after this Jim Crow laws spread across the US to discriminate against the African Americans.
Brown vs. Board of Education was Supreme court case that US laws establishing racial segregation in public schools are unconstitutional as it violated the Fourteenth amendment. Segregation started to decline after this case.
