Answer: I would contend that the main error is the inclusion of the phrase "Edited by Steven van Leeuwen" at the end of the bibliography entry and after a period.
Explanation: Just to elaborate a little on the answer, it can be added that, if you are using as a guide the Chicago Manual of Style, the name of the editor must be placed at the beginning of the entry, following by a comma and the letters "ed." (Van Leeuwen, Steven, ed). However, since this is a book written by another author, who Steven van Leeuwen has edited, his name will appear after the title of the book, followed by the words "edited by."
In addition, the entry should also include the name of the city where the publisher is located: Chicago: A. C. McClurg & Co, 1903.
The final should look like this: Du Bois, W.E.B. <em>The Souls of Black Folk</em>, edited by Steven van Leeuwen. Chicago: A. C. McClurg & Co, 1903.
