How did the Supreme Court case's ruling in Plessy v. Ferguson affect the lives of African Americans?

On May 18th in 1886, the Supreme Court of the United States issued a landmark decision that upheld the constitutionality of racial segregation in the country, under the doctrine known as "separate but equal". The case began when Homer Plessy, an African-american citizen refused to sit in a car for blacks when he was riding the bus. The Court stated that the law that stated racial segregation in the country, was not unconstitutional. As a result of the Supreme Court's decision, public accommodation segregation based on race became a common thing everywhere in the country, even increasing in some areas, specifically in the South. This decision affected the lives of all African-Americans, who watched with horror how the government was ruling in favor of those who wanted to discriminate them.