A historian would first look at the reliability of a source - when it was published and what was happening at the time (context), who wrote it and their qualifications, any bias the author may hold, whether author sources corroborate the source, whether the author has used references, whether the source provides evidence, who the source is representative of and whether the source provides a balanced perspective
In the pivotal case of Plessy v. Ferguson in 1896, the U.S. Supreme Court ruled that racially separate facilities, if equal, did not violate the Constitution. Segregation, the Court said, was not discrimination.
