How did the 1896 Supreme Court decision in the Plessy v. Ferguson case affect segregation in the United States?

Plessy v. Ferguson refers to a US Supreme Court decision taken back in 1896 that upheld the issue of racial segregation. It was prescribed under the "separate but equal" doctrine on constitutional grounds.

The case was the outcome of an incident that had taken place in 1892. An African-American passenger Homer Plessy had refused to take his seat in a railway car reserved for blacks. The Supreme Court passed a ruling that rejected Plessy's argument of violation of constitutional rights.

Further, it ruled that any state law that "implies merely a legal distinction" between the blacks and whites was not in conflict with the 13th and 14th Amendments of the US Constitution.