Answer:
Emmett Till's murder was such a spark in the civil rights movement because there was proof that Emmett was not guilty of what the people accused him of, he was only 14 years old at the time of his death and because the people that killed him admitted in a national newspaper that they killed him and were still found not guilty.
Germany's resumption of unrestricted submarine warfare
The artistic decision to use black and white film despite having access to high quality color techniques is a notable feature of Schindler's list. The use of black and whites allows for a realistic recreation of the WWII era environments, tone and aesthetic.
