They are connected because the fight against fascism during World War II delivered to the forefront the contradictions between America's ideals of democracy and equality and its treatment of racial minorities. Throughout the war, the NAACP and alternative civil rights organizations worked to end discrimination within the military.
The definition of "tone" in literature is the way the author expresses his attitude through his writing. The tone can change very quickly or may remain the same throughout the story. Tone is expressed by your use of syntax, your point of view, your diction, and the level of formality in your writing.