Answer:
Plessy v. Ferguson, 163 U.S. 537 (1896), was a landmark decision of the U.S. Supreme Court that upheld the constitutionality of racial segregation laws for public facilities as long as the segregated facilities were equal in quality – a doctrine that came to be known as "separate but equal".
Explanation:
Why did historians choose to study this topic the correct answer is b
Image result for Which of the following countries was never a member of the League of Nations
The Soviet Union was the only country to be expelled by the League (in 1939, following its invasion of Finland). Despite formulating the concept and signing the Covenant, the United States never joined the League of Nations.
Member: Ecuador; Soviet Union