Answer:
The correct answer is: <em><u>racism and World War II.</u></em>
Explanation:
Joe Louis was a <em>professional boxer from the United States</em> who was heavyweight champion for 12 consecutive years (1937 to 1949). He came from a poor family and was black skin. He started going to a gym where he learned how to box, and his talent attracted professional promoters and good fights. In 1936 he fought against Max Schmeling who was a german boxer considered a stereotype of german race, and that became his most famous opponent and also a good friend of his.
African-American people saw him as hope for inclusion in sports and in society, because even thought slavery was abolished in 1865 with the 13th Amendment, in the United States <u><em>racism</em></u> continued until even after the second half of 1900s. But Joe Louis was liked by people inside and outside the ring and even was recognized as a nationwide US hero. And therefore he was adding to the cause for the end of racism for African-American people.
Also in the height of his career<u><em> World War II</em></u><em> </em>(1939-1945) broke out. He enlisted and was an important promoter for African-American men to enlist the army.