I) The Reconstruction Era and the 1950s and 60s weren't as different as they should be. With different degrees, racism and segregation persisted in XXth century America. African-Americans still couldn't fully exercise their rights as the whites did theirs, and they still suffered violence from white supremacists and authorities.
II) The differences rest in how African-Americans in the 50s and 60s were better mobilized and prepared to defend themselves and fight for their rights. Despite continuous racism, in the 50s and 60s there was more space and sources from which racism could be fought against. There was NAACP, for example, and many public figures famous for fighting racism.
III) From this comparison, we see that one of the Reconstruction's successes was the foundation for legal disputes in favor of African-Americans rights, like the 14th Amendment and the 15th Amendment that provided the legal basis to fight racism and to expand African-americans rights. As for Reconstruction's failures, it didn't dismantle racist structures in the South and didn't succeed in changing culturally how black people were seen, leaving space for racism in its many forms like lynchings and segregation.
