I was not aware of Du Bois' views of Jews in his early career. Perhaps I missed this in my focus on his later works, such as Black Reconstruction in America. I wonder if this early attitude came from his rivalry with Booker T. Washington, who admired the economic success of (some) Jews, and encouraged Blacks to do the same, even if it meant exploiting their fellows. As you point out, his association with liberal and socialist Jews changed his views. Indeed, he appointed a Jewish Communist - Herbert Apthetker - to be his literary executor.

You inspired me to look further into this, which led me to this quote from one of Du Bois' letters to Apthetker regarding revisions to Souls of Black Folks, originally published in 1903:

"I have had a chance to read [The Souls of Black Folk] in part for the first time in years. I find in chapters VII, VIII and IX, five incidental references to Jews. I recall that years ago, Jacob Schiff wrote me criticising these references and that I denied any thought of race or religious prejudice and promised to go over the passages in future editions. These editions succeeded each other without any consultation with me, and evidently the matter slipped out of my mind."

"As I re-read these words today, I see that harm might come if they were allowed to stand as they are. First of all, I am not at all sure that the foreign exploiters to whom I referred ... were in fact Jews.... But even if they were, what I was condemning was the exploitation and not the race nor religion. And I did not, when writing, realize that by stressing the name of the group instead of what some members of the [group] may have done, I was unjustly maligning a people in exactly the same way my folk were then and are now falsely accused.

In view of this and because of the even greater danger of injustice now than then, I want in the event of re-publication [to] change those passages."

In a March 1953 letter to Blue Heron Press, Du Bois asked that the following paragraph be added to the end of "Of the Black Belt":

"In the foregoing chapter, "Jews" have been mentioned five times, and the late Jacob Schiff once complained that this gave an impression of anti-Semitism. This at the time I stoutly denied; but as I read the passages again in the light of subsequent history, I see how I laid myself open to this possible misapprehension. What, of course, I meant to condemn was the exploitation of black labor and that it was in this country and at that time in part a matter of immigrant Jews, was incidental and not essential. My inner sympathy with the Jewish people was expressed better in the last paragraph of page 152. But this illustrates how easily one slips into unconscious condemnation of a whole group."

It is this "unconscious condemnation of a whole group" by generalizing from individuals which we must be vigilant to avoid. I admire Du Bois most for his emphasis on solidarity over "artificial lines of division" which hold us back.