Final answer:
The provided information does not specify the schools Elder Watson Diggs attended; instead, it focuses on the historical debate between Booker T. Washington and W. E. B. Du Bois and does not relate directly to Elder Watson Diggs' educational history.
Step-by-step explanation:
The person in question, Elder Watson Diggs, attended several schools but the provided information does not specifically pertain to his educational history. Instead, it focuses on the history of African American education and notable figures like Booker T. Washington. As the question about the educational background of Elder Watson Diggs remains unanswered based on the provided reference, we cannot offer a factually accurate response about where Elder Watson Diggs went to school without further research. It's important to cross-reference such information with reliable academic sources to ensure the accuracy of historical data.