... starting sometime around 1965, the blacks began the process of expelling the Jews from the Civil Rights movement, as they embraced anti-Semitism and the Arab war for the destruction of Israel. In New York City, this period reached a culmination in the 1968 teachers strike.

The strike was caused by the decision of a black school board in Brownsville, Brooklyn to fire many of the Jewish teachers and administrators from the local schools and replace them with black separatist teachers and administrators. 
The head the teachers union Albert Shanker dated the end of Jewish-black cooperation to the strike. 

While researching my book, yesterday I came across a fascinating FBI report from 1970 that was declassified under the Freedom of Information Act in 2009. 

Titled, "FBI Monograph: 

Fedayeen Impact - Middle East and United States, June 1970," it is focused on the PLO, and Fatah's penetration of the American political Left.  

Here's the link:  

http://www.governmentattic.org/2docs/FBI_Monograph_Fedayeen-Impact_1970.pdf 

In the section on PLO operations in the US, The monograph discussed its outreach to the African American political leadership and the radical white establishment. These sections of the report are fascinating and I recommend you take an hour or so to read the entire document yourself. 

As the report puts it, "Since the June 1967, war, reports emanating from various sources have suggested that the Arabs have co-opted black extremists in the United States to assist the 'struggle' against Israel in the Middle East and in the United States."