The most effective social change campaign or movement during the period of 1945–1970s

Post a 2- to 3-paragraph assessment of what you consider to be the most effective social change campaign or movement during the period of 1945–1970s. Address the following in your posting:
Identify the movement and the timeframe in which it began.
What issue(s) prompted this movement?
Who led this social change effort? What quality(ies) did this individual or group bring to the movement that helped to galvanize supporters?
What key challenges did the movement face?
Why do you consider this movement the most effective social change campaign during the modern civil rights era?
What changes occurred (or are still occurring) because of this movement?
What is still left to accomplish?