What did homer plessy believe would protect his constitutional rights, even as a black american?

Historical background/details:

After the Civil War, in 1868, the 14th Amendment was added to the Constitution.  It stipulated that no state in the United States shall "deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws."

In the decades after the Civil War, however, states in the South began to pass laws that sought to keep white and black society separate.  In the 1880s, a number of  state legislatures began to pass laws requiring railroads to provide separate cars for passengers who were black.  At the heart of the case that became Plessy v. Ferguson was an 1890 law passed in Louisiana in 1890 that required railroads to provide "separate railway carriages for the white and colored races.”

In 1892, Homer Plessy, who was 1/8 black, bought a first class train railroad ticket, took a seat in the whites only section, and then informed the conductor that he was part black.  He was removed from the train and jailed.  He argued for his civil rights before Judge John Howard Ferguson and was found guilty.  His case went all the way to the Supreme Court which at that time upheld the idea of "separate but equal" facilities.

Homer Plessy was correct in his convictions, though.  The 14th Amendment really did protect his consitutional rights.  It just took a while for the nation to come to terms with that reality.  Several decades after Homer Plessy's case, the 1896 Plessy v. Ferguson decision was overturned.  Brown v. Board of Education, decided by the US Supreme Court in 1954, extended civil liberties to all Americans in regard to access to education. The "separate but equal" principle of Plessy v. Ferguson had been applied to education as it had been to transportation. In Topeka, Kansas, Oliver Brown filed a lawsuit after the public school district refused to enroll his daughter in the school closest to their home, making her instead take a bus to a blacks-only school.  Other families joined the Brown family lawsuit.  When it went to the level of the Supreme Court, there were other cases from other parts of the country that the Supreme Court combined with it.  The full name of the case at the Supreme Court level was Oliver Brown, et al. v. Board of Education of Topeka, et al.  The arguments were heard before the Supreme Court in 1952 and 1953, and the Brown v. Board of Education decision was issued  in 1954.   The standard of "separate but equal" was challenged and defeated. Segregation was shown to create inequality, and the Supreme Court unanimously ruled segregation to be unconstitutional.

The 14th Amendment guarantees equal protection to all citizens. This was what the Supreme Court said was being violated by states whose laws supported the segregation of schools.  Section 1 of the 14th Amendment reads as follows:

hitler was elected as a strong leader by germans who felt angry following the treaty of versailles.

the us constitution is a living document, meaning that it can be changed over time as the country changes.