Why was plessy convicted at 30?

Homer Plessy was convicted at age 30 for violating Louisiana's "Separate Car Act," which mandated racial segregation in public transportation. He deliberately sat in a whites-only train car to challenge the constitutionality of the segregation law. His arrest led to the landmark Supreme Court case Plessy v. Ferguson in 1896, which upheld the "separate but equal" doctrine, effectively legitimizing racial segregation in the United States.