As an American distinctly interested in the Civil Rights Movement and the events that lead up too, happened during, and were caused by the Movement I have this question.
Not many textbooks discuss the effect that the assassination of Luther had on the Civil Rights Movement. Surely the unlawful death of their biggest advocate and voice caused unrest of some sort. Less broad questions than above are these.
What effect did the assassination of Luther have on the furthering of the Movement?
How did the political, cultural, and moral goals of the movement change regarding the death of Luther, if they changed at all?
Did the death of Luther cause a significant rise or fall in acceptance of the movement by the politicians and general population?
What were the lasting effects on the African American communities in that time regarding the acceptance of the movement after Luther’s death?
Martin Luther king jr. was assassinated in 1968, right before he was to lead a large march for the working poor. Before his death, the scope of his activism was changing to become what people then considered to be more radical. Even today many of his ideas about equality would cause shudders in certain segments of the population, and much of his image has been whitewashed in modern times to be more palatable.
By 1968, much of the landmark progressions from the 1964 Civil Rights Act, the voting rights act, Heart of Atlanta Motel v. U.S. (which prohibited discrimination for public accommodations) and Brown v. Board had already been accomplished. Unfortunately, progress on civil rights slowed dramatically after King's assassination. Certainly, there were still moments of progress, but there were also setbacks.
De jure, or legal, segregation had been significantly curbed by the time King died, but de facto, or in fact, segregation and discrimination was still rampant. It is the de facto segregation that King was battling before his death, and we still struggle with this today. For example, after King died, new forms of discrimination and subjugation were appearing, such as criminal laws that interestingly targeted people of color, and urban renewal, popular from the 50's to the 70's, which deliberately demolished black communities. Segregation in schools legally ended after Brown v. Board, but statistically speaking schools are as segregated now, if not more so, than they were when the Little Rock Nine had to be escorted by the National Guard to integrate a school.
So, to answer your question in brief, King's assassination effectively marked the end of civil rights and in fact marked the beginning of a new era of discrimination and segregation that is often less easy to identify. If you want to know more, especially as it relates to how criminal justice evolved to act as a new face to discrimination, I suggesting reading Michelle Alexander's book The New Jim Crow, or Paul Butler's Let's Get Free: A Hip Hop Theory of Justice.
I hope this helps!