What was the subject of the louisiana laws upheld by plessy v. ferguson?
a)grandfather clauses
b)poll taxes
c)separate rail facilities
d)women’s suffrage
e)peaceful protest

"Separate rail facilities" was the one subject of the Louisiana laws among the choices given in the question that was upheld by Plessy v. Ferguson. The correct option among all the options that are given in the question is the third option or option "c". I hope that this is the answer that has come to your desired help.