The three major groups of minorities are the emancipated black children of slavery, immigrants, and various natives.
For black people, even if equality hasn't been achieved, there was a rather large increase in quality of life for the overall community, even if it wasn't a uniform increase.
For immigrants, a lot of immigrants were able to improve their quality of life both within their generation and beyond to their next generation.
For various native groups, they are a rounding error compared to the first two groups.