Which of the following is true about the Plessy v. Ferguson case?

The Plessy v. Ferguson case, decided in 1896, is significant because it established the "separate but equal" doctrine, which allowed state-sponsored segregation as long as the separate facilities for the races were deemed equal. The case arose from Homer Plessy's arrest for sitting in a "whites only" railroad car, leading to a legal challenge on the grounds of civil rights. The Supreme Court's ruling effectively legitimized racial segregation, asserting that it did not violate the 14th Amendment's Equal Protection Clause as long as the facilities provided to both white and African American citizens were comparable. This decision had far-reaching consequences for civil rights in the United States, reinforcing institutionalized segregation until it was finally overturned by later rulings, including Brown v. Board of Education in 1954.

The other options do not accurately reflect the ruling of Plessy v. Ferguson, as the case did not declare segregation unconstitutional, nor did it focus on women's voting rights or the use of literacy tests.