There are about three big ones that come off the top of my head. 
- It overruled the Plessy v. Ferguson case, which made Jim Crow and Segregation legal with its famous “separate but equal” ruling. 
- It emboldened the Civil Rights movement, as this major victory gave organizations like the NAACP and CORE a legal platform to combat racism. 
- It redefined the values of America, replacing Segregation with Integration.