Final answer:
The March on Washington in 1963 is identified as the event that solidified moderate white support for the civil rights movement. Martin Luther King Jr.'s nonviolent approach and the widespread influence of his 'I Have a Dream' speech played significant roles in this shift.
Step-by-step explanation:
The event that is most often associated with solidifying moderate white support for the civil rights movement is D) the March on Washington. This momentous event, which took place in August 1963, is remembered for Martin Luther King Jr.'s iconic "I Have a Dream" speech. The passionate call for equality and unity resonated with a broad audience, including moderate white individuals who had not previously been engaged in the movement. The event's peaceful nature, contrasted with the violence sometimes depicted in other protests, further appealed to this group and helped garner its support.
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