Homer Plessy was arrested because he sat down in a train's whites-only car. In 1892, Plessy deliberately challenged the segregation laws in the state of Louisiana by sitting in a whites-only railroad car. He was of mixed heritage, but under the racially discriminatory laws of the time, any person with even a trace of African ancestry was considered "colored" and subject to segregation. Plessy's arrest and subsequent legal case, known as Plessy v. Ferguson, reached the United States Supreme Court. Unfortunately, the Supreme Court ruled against Plessy, establishing the "separate but equal" doctrine that legitimized racial segregation for several decades until it was eventually overturned in the landmark case of Brown v. Board of Education in 1954.