Moved by his investigation of the Springfield Race Riot of 1908 in the state capital of Illinois, he was among the co-founders of the National Association for the Advancement of Colored People (NAACP) in 1909.

He left the Socialist Party because of its anti-war policy, as he believed United States participation in the Great War was needed to defeat the Central Powers.

The boys' maternal grandfather was William Hayden English, a successful businessman in Indiana and the Democratic nominee for vice president in 1880.

In 1906, following a lengthy trip to Russia to report on the abortive Russian Revolution of 1905, he married Anna Strunsky, a Jewish immigrant and an aspiring novelist from San Francisco, who had lived as a child with her family on New York's Lower East Side before they moved to California.

Ethnic whites had attacked blacks, with physical conflict arising out of job competition at the lowest levels and rapid social change in the developing city.

She was one among a number of people, white and black, Christians and Jews, who were moved to create a new organization to work for civil rights.

Du Bois from the Niagara Movement; founding Jewish members included such leaders as Henry Moskowitz, Joel and Arthur Spingarn, Lillian Wald, Walter E. Sachs, and others.