The Plessy vs Fergunson was a court case, where a freedman was convicted guilty of violating the Equal but Separate doctorine.
The fourteenth admendment granted equal rights, but not equal treatment. Which was displayed in this situation.
The justices opinions had been based off the doctrine, and therefore was going to be an unfair tide on the freedman.
One of the justices were actually against racial segregation, so he wasn't completely alone.
This case basically showed that the freedmen were treated much more poorly compared to their fellow white counterparts.
But what occurred was Plessly bought a first class ticket for the rail car, and he was turned down. But he refused to move and was arrested because he violated the Louisiana law that said the rail cars have to be separated, and the separate but equal doctorine.
I personally believe that this had a negative impact on reconstruction, it discouraged blacks/freedmen, and enraged them and freedom fighters.
It just proved that the people who wanted equal rights that they didn't exactly have them, yet.
And it empowered those who supported segregation.