Answer:
The death of Dr. Martin Luther Kind Jr negatively impacted the effort to expand civil rights for African Americans. Yes, his legacy was carried out no matter what and his footprint for African-American rights still stands but his presence was definitely missed as it could have influenced many more marches and events not just for the African-American community but also for other campaigns such as the "Poor-People's Campaign". He would also had continued to speak against the US involvement in the Vietnam war, and probably against many more conflicts in the future.
