What argument did Plessy and legal team make in please v. Ferguson?

In Plessy v. Ferguson, Homer Plessy and his legal team argued that the segregation laws violated the Equal Protection Clause of the Fourteenth Amendment. They contended that the Louisiana law requiring separate railway cars for black and white passengers was discriminatory and perpetuated racial inequality. Plessy's team asserted that enforced segregation created a stigma of inferiority among African Americans, which was inherently unjust. However, the Supreme Court ultimately upheld the "separate but equal" doctrine, legitimizing state-sponsored segregation.