Picture courtesy of biography.com
The next important speech I believe is “Other America” by Martin Luther King delivered in 1968 a few months before his assassination.

The speech is famous for the expression

“a kind of socialism for the rich and rugged hard individualistic capitalism for the poor.”

King was describing the many benefits given to whites to better themselves, being opportunities not given to blacks. 

We have a similar crisis emerging today, where the gap between rich and poor is increasing. 

http://genius.com/Martin-luther-king-jr-the-other-america-annotated

King was keen to repair the social fabric by providing opportunities for everyone. This sentiment is as important today as it was back then. He knew it was a difficult struggle.