From a piece on the “Brave and tragic heroes of civil rights” in the Jewish Chronicle:

Estimates suggest that Jews made up half of the young people who participated in Freedom Summer…

Clarence Jones, a black lawyer who began working with Martin Luther King in the early 1960s, says the civil rights leader understood that enlisting whites was essential to realising his dream. “Of that white majority,” Jones suggests, “the most important constituent part was the Jewish community.”

But Jews were not new recruits to the civil rights cause. Columbia University professor Joel Spingarn helped establish the National Association for the Advance of Coloured People in 1909 and served as its chairman for 25 years. Jews were heavily involved in the Urban League, formed in 1911 to help black migrants from the rural south, while Jewish philanthropists gave generously to African-American causes.