Final answer:
The person who worked with Ida Wells-Barnett to prevent racial segregation in Chicago public schools was W. E. B. Du Bois, a key figure in civil rights history and a co-founder of the NAACP.
Step-by-step explanation:
Working with the Black journalist and educator Ida Wells-Barnett, the person in question who successfully prevented racial segregation in the Chicago public schools was none other than the renowned sociologist and historian W. E. B. Du Bois. Ida Wells-Barnett herself was a tireless advocate for civil rights and played a significant role in the anti-lynching movement as well as the fight for gender and race equality. Together with W. E. B. Du Bois, who was instrumental in the founding of the National Association for the Advancement of Colored People (NAACP) and served as the editor of its magazine, The Crisis, they formed a powerful alliance in battling against racial segregation, which was a prevalent societal issue during their lifetime.